diff --git a/.docker/Dockerfile b/.docker/Dockerfile
index dd46470..d7bc22c 100644
--- a/.docker/Dockerfile
+++ b/.docker/Dockerfile
@@ -1,14 +1,7 @@
-ARG PHP_VERSION=8.2
-ARG PHPUNIT_VERSION=10.4.0
-ARG PHPSTAN_VERSION=1.10.38
+ARG PHP_VERSION=8.5
 
 FROM php:${PHP_VERSION}-cli-alpine
 COPY --from=composer /usr/bin/composer /usr/bin/composer
 
-ARG PHPUNIT_VERSION
-ARG PHPSTAN_VERSION
-
 RUN docker-php-ext-install bcmath && docker-php-ext-enable bcmath
-RUN wget -O phpunit https://phar.phpunit.de/phpunit-${PHPUNIT_VERSION}.phar && chmod +x phpunit
-RUN wget -O phpstan https://github.com/phpstan/phpstan/releases/download/${PHPSTAN_VERSION}/phpstan.phar && chmod +x phpstan
 
diff --git a/.env b/.env
index af97ce2..93ca64f 100644
--- a/.env
+++ b/.env
@@ -1,3 +1 @@
-PHP_VERSION=8.2
-PHPUNIT_VERSION=10.4.0
-PHPSTAN_VERSION=1.10.38
+PHP_VERSION=8.5
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 191fdc4..e40c7f8 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,14 +9,14 @@ on:
 
 jobs:
   testsuite:
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
     strategy:
       fail-fast: false
       matrix:
-        php-version: ['8.1', '8.3', '8.5']
+        php-version: ['8.2', '8.3', '8.4', '8.5']
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
 
     - name: Setup PHP
       uses: shivammathur/setup-php@v2
@@ -32,29 +32,29 @@ jobs:
 
     - name: Run PHPUnit
       run: |
-        if [[ ${{ matrix.php-version }} == '8.1' ]]; then
+        if [[ ${{ matrix.php-version }} == '8.2' ]]; then
           vendor/bin/phpunit --coverage-clover=coverage.xml
         else
           vendor/bin/phpunit
         fi
 
     - name: Code Coverage Report
-      if: success() && matrix.php-version == '8.1'
-      uses: codecov/codecov-action@v4
+      if: success() && matrix.php-version == '8.2'
+      uses: codecov/codecov-action@v5
       with:
         token: ${{ secrets.CODECOV_TOKEN }}
 
   validation:
     name: Coding Standard & Static Analysis
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
 
     - name: Setup PHP
       uses: shivammathur/setup-php@v2
       with:
-        php-version: '8.1'
+        php-version: '8.2'
         extensions: mbstring, intl, bcmath
         coverage: none
 
diff --git a/README.md b/README.md
index 518f735..9193433 100644
--- a/README.md
+++ b/README.md
@@ -3,7 +3,7 @@
 [![CI](https://github.com/php-collective/decimal-object/actions/workflows/ci.yml/badge.svg?branch=master)](https://github.com/php-collective/decimal-object/actions/workflows/ci.yml)
 [![codecov](https://codecov.io/gh/php-collective/decimal-object/branch/master/graph/badge.svg?token=L1thFB9nOG)](https://codecov.io/gh/php-collective/decimal-object)
 [![Latest Stable Version](https://poser.pugx.org/php-collective/decimal-object/v/stable.svg)](https://packagist.org/packages/php-collective/decimal-object)
-[![Minimum PHP Version](https://img.shields.io/badge/php-%3E%3D%208.1-8892BF.svg)](https://php.net/)
+[![Minimum PHP Version](https://img.shields.io/badge/php-%3E%3D%208.2-8892BF.svg)](https://php.net/)
 [![PHPStan](https://img.shields.io/badge/PHPStan-level%208-brightgreen.svg?style=flat)](https://phpstan.org/)
 [![License](https://poser.pugx.org/php-collective/decimal-object/license)](https://packagist.org/packages/php-collective/decimal-object)
 
@@ -26,7 +26,7 @@ Monetary values themselves could be handled also with [brick/money](https://gith
 
 For details see the [wiki](https://github.com/php-collective/decimal-object/wiki).
 
-Note: If you are looking for pre PHP 8.1 versions, check out the [legacy library](https://github.com/spryker/decimal-object).
+Note: PHP 8.1 is covered by the 1.3 releases. For anything older, check out the [legacy library](https://github.com/spryker/decimal-object).
 
 ## Features
 
@@ -40,6 +40,7 @@ Note: If you are looking for pre PHP 8.1 versions, check out the [legacy library
 
 ### Requirements
 
+- PHP 8.2+
 - `bcmath` PHP extension enabled
 
 ### Composer (preferred)
diff --git a/compose.yaml b/compose.yaml
index 84edd30..7d9c008 100644
--- a/compose.yaml
+++ b/compose.yaml
@@ -6,9 +6,7 @@ services:
             context: .
             dockerfile: .docker/Dockerfile
             args:
-                PHP_VERSION: "${PHP_VERSION:-8.2}"
-                PHPUNIT_VERSION: "${PHPUNIT_VERSION:-10.4.0}"
-                PHPSTAN_VERSION: "${PHPSTAN_VERSION:-1.10.38}"
+                PHP_VERSION: "${PHP_VERSION:-8.5}"
         volumes:
             - ./:/code
         working_dir: /code
diff --git a/composer.json b/composer.json
index ae80adf..c37719e 100644
--- a/composer.json
+++ b/composer.json
@@ -3,6 +3,14 @@
     "description": "PHP decimal handling as value object",
     "license": "MIT",
     "type": "library",
+    "keywords": [
+        "decimal",
+        "value-object",
+        "bcmath",
+        "precision",
+        "arbitrary-precision",
+        "math"
+    ],
     "authors": [
         {
             "name": "The PHP Collective",
@@ -13,15 +21,19 @@
             "homepage": "https://spryker.com"
         }
     ],
+    "support": {
+        "issues": "https://github.com/php-collective/decimal-object/issues",
+        "source": "https://github.com/php-collective/decimal-object"
+    },
     "require": {
-        "php": ">=8.1",
+        "php": ">=8.2",
         "ext-bcmath": "*",
         "ext-json": "*"
     },
     "require-dev": {
-        "php-collective/code-sniffer": "^0.2.1",
+        "php-collective/code-sniffer": "^0.6.8",
         "phpstan/phpstan": "^2.0.0",
-        "phpunit/phpunit": "^10.5.45 || ^11.0.0 || ^12.0.0 || ^13.0.0"
+        "phpunit/phpunit": "^11.5.0 || ^12.0.0 || ^13.0.0"
     },
     "minimum-stability": "stable",
     "prefer-stable": true,
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index ef3d67a..eca8d3f 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -1,5 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <phpunit
+        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
         colors="true"
         bootstrap="vendor/autoload.php"
 >
diff --git a/src/Decimal.php b/src/Decimal.php
index 8f005ad..f92677b 100644
--- a/src/Decimal.php
+++ b/src/Decimal.php
@@ -74,6 +74,7 @@ public function __construct(object|string|float|int $value, ?int $scale = null,
 
         $this->setValue($value, $scale);
         $this->setScale($scale, $strict);
+        $this->normalizeZero();
     }
 
     /**
@@ -105,11 +106,16 @@ protected function parseValue(object|string|float|int $value): string
             throw new InvalidArgumentException('Invalid non numeric value');
         }
 
-        if (!is_string($value)) {
-            $value = (string)$value;
+        if (is_float($value)) {
+            if (!is_finite($value)) {
+                throw new InvalidArgumentException('Invalid non finite value');
+            }
+
+            // PHP renders large and small floats as `1.0E+25`, that zero is not a significant digit.
+            return str_replace('.0E', 'E', (string)$value);
         }
 
-        return $value;
+        return (string)$value;
     }
 
     /**
@@ -120,22 +126,13 @@ protected function parseValue(object|string|float|int $value): string
     protected function normalizeValue(string $value): string
     {
         $value = trim($value);
-        /** @var string $value */
-        $value = preg_replace(
-            [
-                '/^^(-?)(\.)(.*)$/', // omitted leading zero
-                '/^0+(.)(\..*)?$/', // multiple leading zeros
-                '/^(\+(.*)|(-)(0))$/', // leading positive sign, tolerate minus zero too
-            ],
-            [
-                '${1}0.${3}',
-                '${1}${2}',
-                '${4}${2}',
-            ],
-            $value,
-        );
+        $sign = str_starts_with($value, '-') ? '-' : '';
+        $value = ltrim(ltrim($value, '+-'), '0');
+        if ($value === '' || !ctype_digit($value[0])) {
+            $value = '0' . $value;
+        }
 
-        return $value;
+        return $sign . $value;
     }
 
     /**
@@ -165,7 +162,7 @@ public static function create(object|string|float|int $value, ?int $scale = null
      *
      * This method is equivalent to the `==` operator.
      *
-     * @param static|string|float|int $value
+     * @param self|string|float|int $value
      *
      * @return bool TRUE if this decimal is considered equal to the given value.
      *  Equal decimal values tie-break on precision.
@@ -176,7 +173,7 @@ public function equals(self|string|float|int $value): bool
     }
 
     /**
-     * @param static|string|float|int $value
+     * @param self|string|float|int $value
      *
      * @return bool
      */
@@ -186,7 +183,7 @@ public function greaterThan(self|string|float|int $value): bool
     }
 
     /**
-     * @param static|string|float|int $value
+     * @param self|string|float|int $value
      *
      * @return bool
      */
@@ -196,7 +193,7 @@ public function lessThan(self|string|float|int $value): bool
     }
 
     /**
-     * @param static|string|float|int $value
+     * @param self|string|float|int $value
      *
      * @return bool
      */
@@ -208,7 +205,7 @@ public function greaterThanOrEquals(self|string|float|int $value): bool
     /**
      * @deprecated Use {@link greaterThanOrEquals()} instead.
      *
-     * @param static|string|float|int $value
+     * @param self|string|float|int $value
      *
      * @return bool
      */
@@ -218,7 +215,7 @@ public function greatherThanOrEquals(self|string|float|int $value): bool
     }
 
     /**
-     * @param static|string|float|int $value
+     * @param self|string|float|int $value
      *
      * @return bool
      */
@@ -235,7 +232,7 @@ public function lessThanOrEquals(self|string|float|int $value): bool
      * - `0` if the instance is equal to $value, or
      * - `1` if the instance is greater than $value.
      *
-     * @param static|string|float|int $value
+     * @param self|string|float|int $value
      *
      * @return int
      */
@@ -250,7 +247,7 @@ public function compareTo(self|string|float|int $value): int
     /**
      * Add $value to this Decimal and return the sum as a new Decimal.
      *
-     * @param static|string|float|int $value
+     * @param self|string|float|int $value
      * @param int|null $scale Decimal places in the result. Omit to enable auto-detection.
      *
      * @return static
@@ -284,7 +281,7 @@ protected function resultScale(self $a, self $b, ?int $scale = null): int
      * Subtract $value from this Decimal and return the difference as a new
      * Decimal.
      *
-     * @param static|string|float|int $value
+     * @param self|string|float|int $value
      * @param int|null $scale Decimal places in the result. Omit to enable auto-detection.
      *
      * @return static
@@ -392,12 +389,12 @@ public function isPositive(): bool
     /**
      * Multiply this Decimal by $value and return the product as a new Decimal.
      *
-     * @param static|string|float|int $value
+     * @param self|string|float|int $value
      * @param int|null $scale Decimal places in the result. Omit to enable auto-detection.
      *
      * @return static
      */
-    public function multiply(self|string|int|float $value, ?int $scale = null): static
+    public function multiply(self|string|float|int $value, ?int $scale = null): static
     {
         $decimal = static::create($value);
         if ($scale === null) {
@@ -410,14 +407,14 @@ public function multiply(self|string|int|float $value, ?int $scale = null): stat
     /**
      * Divide this Decimal by $value and return the quotient as a new Decimal.
      *
-     * @param static|string|float|int $value
+     * @param self|string|float|int $value
      * @param int $scale Decimal places in the result
      *
      * @throws \DivisionByZeroError if $value is zero.
      *
      * @return static
      */
-    public function divide(self|string|int|float $value, int $scale): static
+    public function divide(self|string|float|int $value, int $scale): static
     {
         $decimal = static::create($value);
         if ($decimal->isZero()) {
@@ -430,7 +427,7 @@ public function divide(self|string|int|float $value, int $scale): static
     /**
      * This method is equivalent to the ** operator.
      *
-     * @param static|string|int $exponent
+     * @param self|string|int $exponent
      * @param int|null $scale Decimal places in the result. Omit to enable auto-detection.
      *
      * @return static
@@ -441,7 +438,7 @@ public function pow(self|string|int $exponent, ?int $scale = null): static
             $scale = $this->scale();
         }
 
-        return new static(bcpow((string)$this, (string)$exponent, $scale));
+        return new static(bcpow((string)$this, (string)static::create($exponent), $scale));
     }
 
     /**
@@ -463,7 +460,7 @@ public function sqrt(?int $scale = null): static
     /**
      * This method is equivalent to the % operator.
      *
-     * @param static|string|int $value
+     * @param self|string|int $value
      * @param int|null $scale Decimal places in the result. Omit to enable auto-detection.
      *
      * @return static
@@ -474,57 +471,48 @@ public function mod(self|string|int $value, ?int $scale = null): static
             $scale = $this->scale();
         }
 
-        return new static(bcmod((string)$this, (string)$value, $scale));
+        return new static(bcmod((string)$this, (string)static::create($value), $scale));
     }
 
     /**
      * @param int $scale Decimal places in the result (only used with mode "half up")
-     * @param int $roundMode
+     * @param int $roundMode ROUND_HALF_UP, ROUND_CEIL or ROUND_FLOOR. Anything else rounds half up.
+     *
+     * @throws \InvalidArgumentException
      *
      * @return static
      */
     public function round(int $scale = 0, int $roundMode = self::ROUND_HALF_UP): static
     {
-        $exponent = $scale + 1;
+        if ($scale < 0) {
+            throw new InvalidArgumentException('Scale must be >= 0.');
+        }
 
-        switch ($roundMode) {
-            case static::ROUND_FLOOR:
-                $stringValue = (string)$this;
+        // Floor and ceil always round to a whole number in 1.x, the scale only labels the result.
+        $directed = in_array($roundMode, [static::ROUND_FLOOR, static::ROUND_CEIL], true);
+        $places = $directed ? 0 : $scale;
 
-                // If already an integer, return as is
-                if (!str_contains($stringValue, '.')) {
-                    return new static($stringValue, $scale);
-                }
+        $value = (string)$this;
+        $truncated = bcadd($value, '0', $places);
+        if (bccomp($value, $truncated, $this->scale()) === 0) {
+            return new static($truncated, $scale);
+        }
 
-                // For positive values, truncate the decimal part (round down)
-                if (!$this->isNegative()) {
-                    return new static(bcsub($stringValue, bcmod($stringValue, '1'), 0), $scale);
-                }
+        switch ($roundMode) {
+            case static::ROUND_FLOOR:
+                $result = $this->isNegative() ? bcsub($truncated, '1', 0) : $truncated;
 
-                // For negative values, round down away from zero
-                return new static(bcsub($stringValue, '1', 0), $scale);
+                break;
             case static::ROUND_CEIL:
-                $stringValue = (string)$this;
-
-                // If already an integer, return as is
-                if (!str_contains($stringValue, '.')) {
-                    return new static($stringValue, $scale);
-                }
+                $result = $this->isNegative() ? $truncated : bcadd($truncated, '1', 0);
 
-                // If negative, truncate (remove decimals without adding 1)
-                if ($this->isNegative()) {
-                    return new static(bcsub($stringValue, '0', 0), $scale);
-                }
-
-                // Otherwise, round up for positive numbers
-                return new static(bcadd($stringValue, '1', 0), $scale);
-            case static::ROUND_HALF_UP:
+                break;
             default:
-                $e = bcpow('10', (string)$exponent);
-                $v = bcdiv(bcadd(bcmul((string)$this, $e, 0), $this->isNegative() ? '-5' : '5'), $e, $scale);
+                $e = bcpow('10', (string)($scale + 1));
+                $result = bcdiv(bcadd(bcmul($value, $e, 0), $this->isNegative() ? '-5' : '5'), $e, $scale);
         }
 
-        return new static($v, $scale);
+        return new static($result, $scale);
     }
 
     /**
@@ -610,7 +598,9 @@ public function toInt(): int
      */
     public function isBigInteger(): bool
     {
-        return bccomp($this->integralPart, (string)PHP_INT_MAX) === 1 || bccomp($this->integralPart, (string)PHP_INT_MIN) === -1;
+        $value = ($this->negative ? '-' : '') . $this->integralPart;
+
+        return bccomp($value, (string)PHP_INT_MAX) === 1 || bccomp($value, (string)PHP_INT_MIN) === -1;
     }
 
     /**
@@ -618,8 +608,7 @@ public function isBigInteger(): bool
      */
     public function isBigDecimal(): bool
     {
-        return $this->isBigInteger() ||
-            bccomp($this->fractionalPart, (string)PHP_INT_MAX) === 1 || bccomp($this->fractionalPart, (string)PHP_INT_MIN) === -1;
+        return $this->isBigInteger() || bccomp($this->fractionalPart ?: '0', (string)PHP_INT_MAX) === 1;
     }
 
     /**
@@ -635,38 +624,29 @@ public function isBigDecimal(): bool
      */
     public function toScientific(): string
     {
-        if ($this->integralPart) {
-            $exponent = 0;
-            $integralPart = $this->integralPart;
-            while ($integralPart >= 10) {
-                $integralPart /= 10;
-                $exponent++;
-            }
+        if ($this->isZero()) {
+            return $this->toString() . static::EXP_MARK . '0';
+        }
 
-            $value = (string)$integralPart;
-            if (!str_contains($value, '.')) {
-                $value .= '.';
+        if ($this->integralPart !== '0') {
+            $exponent = strlen($this->integralPart) - 1;
+            $digits = $this->integralPart . $this->fractionalPart;
+            if ($this->fractionalPart === '') {
+                $digits = rtrim($digits, '0');
             }
-            $value .= $this->fractionalPart;
         } else {
-            $exponent = -1;
-            // 00002
-            // 20000
-            $fractionalPart = $this->fractionalPart;
-            while (str_starts_with($fractionalPart, '0')) {
-                $fractionalPart = substr($fractionalPart, 1);
-                $exponent--;
-            }
-
-            $pos = abs($exponent) - 1;
-            $value = substr($this->fractionalPart, $pos, 1) . '.' . substr($this->fractionalPart, $pos + 1);
+            $digits = ltrim($this->fractionalPart, '0');
+            $exponent = strlen($digits) - strlen($this->fractionalPart) - 1;
         }
 
+        // The radix mark stays even without decimals (`5.e0`) in 1.x.
+        $value = $digits[0] . static::RADIX_MARK . substr($digits, 1);
+
         if ($this->negative) {
             $value = '-' . $value;
         }
 
-        return $value . 'e' . $exponent;
+        return $value . static::EXP_MARK . $exponent;
     }
 
     /**
@@ -744,6 +724,7 @@ protected function copy(?string $integerPart = null, ?string $decimalPart = null
         if ($negative !== null) {
             $clone->negative = $negative;
         }
+        $clone->normalizeZero();
 
         return $clone;
     }
@@ -824,39 +805,33 @@ protected function fromFloat(string $value): void
      */
     protected function fromScientific(string $value, ?int $scale): void
     {
-        $pattern = '/^(-?)(\d+(?:' . static::RADIX_MARK . '\d*)?|' .
-            '[' . static::RADIX_MARK . ']' . '\d+)' . static::EXP_MARK . '(-?\d*)?$/i';
-        preg_match($pattern, $value, $matches);
-        if (!$matches) {
+        $pattern = '/^(-?)(\d+)(?:' . preg_quote(static::RADIX_MARK, '/') . '(\d*))?' . static::EXP_MARK . '([+-]?\d+)$/i';
+        if (preg_match($pattern, $value, $matches) !== 1) {
             throw new InvalidArgumentException('Invalid scientific value/notation: ' . $value);
         }
 
         $this->negative = $matches[1] === '-';
-        /** @var string $value */
-        $value = preg_replace('/\b\.0$/', '', $matches[2]);
-        $exp = (int)$matches[3];
+        $integralPart = $matches[2];
+        // A mantissa of `1.0` is read as `1` in 1.x.
+        $fractionalPart = $matches[3] === '0' ? '' : $matches[3];
+        $exp = (int)$matches[4];
 
         if ($exp < 0) {
-            $this->integralPart = '0';
-            /** @var string $value */
-            $value = preg_replace('/^(\d+)(\.)?(\d+)$/', '${1}${3}', $value, 1);
-            $this->fractionalPart = str_repeat('0', -$exp - 1) . $value;
-
-            if ($scale !== null) {
-                $this->fractionalPart = str_pad($this->fractionalPart, $scale, '0');
-            }
+            $integralPart = str_pad($integralPart, -$exp + 1, '0', STR_PAD_LEFT);
+            $fractionalPart = substr($integralPart, $exp) . $fractionalPart;
+            $integralPart = substr($integralPart, 0, $exp);
         } else {
-            $this->integralPart = bcmul($matches[2], bcpow('10', (string)$exp));
+            $integralPart .= substr(str_pad($fractionalPart, $exp, '0'), 0, $exp);
+            $fractionalPart = substr($fractionalPart, $exp);
+        }
 
-            $pos = strlen($this->integralPart);
-            if (str_contains($value, '.')) {
-                $pos++;
-            }
-            $this->fractionalPart = rtrim(substr($value, $pos), '.');
+        $this->integralPart = ltrim($integralPart, '0') ?: '0';
+        $this->fractionalPart = $fractionalPart;
 
-            if ($scale !== null) {
-                $this->fractionalPart = str_pad($this->fractionalPart, $scale - strlen($this->integralPart), '0');
-            }
+        if ($scale !== null) {
+            // 1.x pads positive exponents to the scale minus the integral digits.
+            $length = $exp < 0 ? $scale : $scale - strlen($this->integralPart);
+            $this->fractionalPart = str_pad($this->fractionalPart, $length, '0');
         }
     }
 
@@ -870,6 +845,11 @@ protected function fromScientific(string $value, ?int $scale): void
      */
     protected function setScale(?int $scale, bool $strict): void
     {
+        if ($scale !== null && $scale < 0) {
+            throw new InvalidArgumentException('Scale must be >= 0.');
+        }
+
+        // A scale of 0 is treated like no scale in 1.x and does not cut off decimals.
         $calculatedScale = strlen($this->fractionalPart);
         if ($scale && $calculatedScale > $scale) {
             if ($strict) {
@@ -881,4 +861,16 @@ protected function setScale(?int $scale, bool $strict): void
 
         $this->scale = $scale ?? $calculatedScale;
     }
+
+    /**
+     * Zero has no sign, `-0.00` would otherwise report as negative.
+     *
+     * @return void
+     */
+    protected function normalizeZero(): void
+    {
+        if ($this->negative && $this->isZero()) {
+            $this->negative = false;
+        }
+    }
 }
diff --git a/tests/DecimalTest.php b/tests/DecimalTest.php
index 7ba553f..aa5ad49 100644
--- a/tests/DecimalTest.php
+++ b/tests/DecimalTest.php
@@ -12,6 +12,7 @@
 use DivisionByZeroError;
 use InvalidArgumentException;
 use PhpCollective\DecimalObject\Decimal;
+use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\TestCase;
 use Stringable;
 use TypeError;
@@ -24,7 +25,7 @@ class DecimalTest extends TestCase
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('baseProvider')]
+    #[DataProvider('baseProvider')]
     public function testNewObject(mixed $value, string $expected): void
     {
         $decimal = new Decimal($value);
@@ -50,7 +51,7 @@ public function testNewObjectScientific(): void
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('baseProvider')]
+    #[DataProvider('baseProvider')]
     public function testCreate(mixed $value, string $expected): void
     {
         $decimal = Decimal::create($value);
@@ -142,7 +143,7 @@ public function __toString(): string
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('invalidValuesProvider')]
+    #[DataProvider('invalidValuesProvider')]
     public function testNewObjectWithInvalidValueThrowsException(mixed $value): void
     {
         $this->expectException(InvalidArgumentException::class);
@@ -169,7 +170,7 @@ public static function invalidValuesProvider(): array
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('truncateProvider')]
+    #[DataProvider('truncateProvider')]
     public function testTruncate(mixed $input, int $scale, string $expected): void
     {
         $decimal = Decimal::create($input);
@@ -197,7 +198,7 @@ public static function truncateProvider(): array
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('integerProvider')]
+    #[DataProvider('integerProvider')]
     public function testIsInteger(mixed $value, bool $expected): void
     {
         $decimal = Decimal::create($value);
@@ -229,7 +230,7 @@ public static function integerProvider(): array
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('zeroProvider')]
+    #[DataProvider('zeroProvider')]
     public function testIsZero(mixed $value, bool $expected): void
     {
         $decimal = Decimal::create($value);
@@ -260,7 +261,7 @@ public static function zeroProvider(): array
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('compareZeroProvider')]
+    #[DataProvider('compareZeroProvider')]
     public function testIsPositive(mixed $input, int $expected): void
     {
         $decimal = Decimal::create($input);
@@ -273,7 +274,7 @@ public function testIsPositive(mixed $input, int $expected): void
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('compareZeroProvider')]
+    #[DataProvider('compareZeroProvider')]
     public function testIsNegative(mixed $input, int $expected): void
     {
         $decimal = Decimal::create($input);
@@ -307,7 +308,7 @@ public static function compareZeroProvider(): array
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('scaleProvider')]
+    #[DataProvider('scaleProvider')]
     public function testScale(mixed $input, int $expected): void
     {
         $decimal = Decimal::create($input);
@@ -338,7 +339,7 @@ public static function scaleProvider(): array
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('scientificProvider')]
+    #[DataProvider('scientificProvider')]
     public function testToScientific(mixed $value, string $expected): void
     {
         $decimal = Decimal::create($value);
@@ -411,7 +412,7 @@ public function testToFloat(): void
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('bigFloatDataProvider')]
+    #[DataProvider('bigFloatDataProvider')]
     public function testToFloatForBigDecimalThrowsAnException(string $value): void
     {
         $decimal = Decimal::create($value);
@@ -450,7 +451,7 @@ public function testToInt(): void
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('bigIntDataProvider')]
+    #[DataProvider('bigIntDataProvider')]
     public function testToIntForBigIntThrowsAnException(string $value): void
     {
         $decimal = Decimal::create($value);
@@ -605,7 +606,7 @@ public function testEquals(): void
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('roundProvider')]
+    #[DataProvider('roundProvider')]
     public function testRound(mixed $value, int $scale, string $expected): void
     {
         $decimal = Decimal::create($value);
@@ -664,7 +665,7 @@ public static function roundProvider(): array
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('floorProvider')]
+    #[DataProvider('floorProvider')]
     public function testFloor(mixed $value, string $expected): void
     {
         $decimal = Decimal::create($value);
@@ -717,7 +718,7 @@ public static function floorProvider(): array
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('ceilProvider')]
+    #[DataProvider('ceilProvider')]
     public function testCeil(mixed $value, string $expected): void
     {
         $decimal = Decimal::create($value);
@@ -770,7 +771,7 @@ public static function ceilProvider(): array
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('compareProvider')]
+    #[DataProvider('compareProvider')]
     public function testGreaterThan(mixed $a, mixed $b, int $expected): void
     {
         $decimal = Decimal::create($a);
@@ -784,7 +785,7 @@ public function testGreaterThan(mixed $a, mixed $b, int $expected): void
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('compareProvider')]
+    #[DataProvider('compareProvider')]
     public function testLessThan(mixed $a, mixed $b, int $expected): void
     {
         $decimal = Decimal::create($a);
@@ -798,7 +799,7 @@ public function testLessThan(mixed $a, mixed $b, int $expected): void
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('compareProvider')]
+    #[DataProvider('compareProvider')]
     public function testGreaterEquals(mixed $a, mixed $b, int $expected): void
     {
         $decimal = Decimal::create($a);
@@ -812,7 +813,7 @@ public function testGreaterEquals(mixed $a, mixed $b, int $expected): void
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('compareProvider')]
+    #[DataProvider('compareProvider')]
     public function testLessEquals(mixed $a, mixed $b, int $expected): void
     {
         $decimal = Decimal::create($a);
@@ -876,7 +877,7 @@ public function testSubtract(): void
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('multiplicationProvider')]
+    #[DataProvider('multiplicationProvider')]
     public function testMultiply(mixed $a, mixed $b, ?int $scale, string $expected): void
     {
         $decimal = Decimal::create($a);
@@ -915,7 +916,7 @@ public static function multiplicationProvider(): array
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('multiplicationLegacyProvider')]
+    #[DataProvider('multiplicationLegacyProvider')]
     public function testMultiplyLegacy(mixed $a, mixed $b, ?int $scale, string $expected): void
     {
         $decimal = Decimal::create($a);
@@ -940,7 +941,7 @@ public static function multiplicationLegacyProvider(): array
      *
      * @return void
      */
-    #[\PHPUnit\Framework\Attributes\DataProvider('divisionProvider')]
+    #[DataProvider('divisionProvider')]
     public function testDivide(mixed $a, mixed $b, int $scale, string $expected): void
     {
         $decimal = Decimal::create($a);
@@ -1049,4 +1050,226 @@ public function testPrecisionLossFail(): void
 
         Decimal::create('0.123', 2, true);
     }
+
+    /**
+     * @param mixed $value
+     * @param string $expected
+     *
+     * @return void
+     */
+    #[DataProvider('normalizationProvider')]
+    public function testNewObjectNormalization(mixed $value, string $expected): void
+    {
+        $this->assertSame($expected, (string)new Decimal($value));
+    }
+
+    /**
+     * @return array
+     */
+    public static function normalizationProvider(): array
+    {
+        return [
+            'leading zeros' => ['0010', '10'],
+            'negative leading zeros' => ['-007', '-7'],
+            'positive sign leading zeros' => ['+007', '7'],
+            'positive sign omitted zero' => ['+.5', '0.5'],
+            'negative zero with decimals' => ['-0.0', '0.0'],
+            'negative double zero' => ['-00', '0'],
+            'trailing radix' => ['5.', '5'],
+            'explicit positive exponent' => ['1e+5', '100000'],
+            'uppercase exponent' => ['1E5', '100000'],
+            'multi digit mantissa' => ['12.5e-1', '1.25'],
+            'integer mantissa' => ['100e-2', '1.00'],
+            'integer mantissa trailing zero' => ['120e-1', '12.0'],
+            'long mantissa' => ['123.456e-2', '1.23456'],
+            'negative mantissa' => ['-1.5e-2', '-0.015'],
+            'omitted zero mantissa' => ['.5e1', '5'],
+            'small mantissa' => ['0.00012e3', '0.12'],
+            'zero exponent' => ['1.5e0', '1.5'],
+            'negative zero exponent' => ['-0e5', '0'],
+            'zero mantissa' => ['0.0e-3', '0.000'],
+            'large float' => [1e25, '10000000000000000000000000'],
+            'small float' => [1.5e-7, '0.00000015'],
+            'negative zero float' => [-0.0, '0'],
+        ];
+    }
+
+    /**
+     * @param float $value
+     *
+     * @return void
+     */
+    #[DataProvider('nonFiniteProvider')]
+    public function testNewObjectNonFiniteFloat(float $value): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+
+        new Decimal($value);
+    }
+
+    /**
+     * @return array
+     */
+    public static function nonFiniteProvider(): array
+    {
+        return [
+            'inf' => [INF],
+            'negative inf' => [-INF],
+            'nan' => [NAN],
+        ];
+    }
+
+    /**
+     * @return void
+     */
+    public function testNewObjectNegativeScale(): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+
+        new Decimal('1.56', -1);
+    }
+
+    /**
+     * @return void
+     */
+    public function testNewObjectScientificWithScale(): void
+    {
+        $this->assertSame('0.001200', (string)new Decimal('1.2e-3', 6));
+        $this->assertSame('0.0012', (string)new Decimal('1.23456e-3', 4));
+    }
+
+    /**
+     * @return void
+     */
+    public function testNoNegativeZero(): void
+    {
+        $decimal = new Decimal('-0.0');
+        $this->assertFalse($decimal->isNegative());
+        $this->assertSame(0, $decimal->sign());
+
+        $this->assertSame('0', (string)(new Decimal('0'))->negate());
+        $this->assertSame('0.00', (string)(new Decimal('0.00'))->negate());
+        $this->assertSame('0', (string)(new Decimal('-0.5'))->truncate());
+        $this->assertSame('0.0', (string)(new Decimal('-0.05'))->truncate(1));
+        $this->assertSame('0.00', (string)new Decimal('-0.001', 2));
+        $this->assertFalse((new Decimal('-0.5'))->truncate()->isNegative());
+    }
+
+    /**
+     * @param string $value
+     * @param int $scale
+     * @param int $mode
+     * @param string $expected
+     *
+     * @return void
+     */
+    #[DataProvider('roundModeProvider')]
+    public function testRoundMode(string $value, int $scale, int $mode, string $expected): void
+    {
+        $this->assertSame($expected, (string)(new Decimal($value))->round($scale, $mode));
+    }
+
+    /**
+     * @return array
+     */
+    public static function roundModeProvider(): array
+    {
+        return [
+            'floor negative whole' => ['-1.0', 0, Decimal::ROUND_FLOOR, '-1'],
+            'floor positive whole' => ['1.00', 0, Decimal::ROUND_FLOOR, '1'],
+            'floor negative' => ['-1.5', 0, Decimal::ROUND_FLOOR, '-2'],
+            'ceil positive whole' => ['1.0', 0, Decimal::ROUND_CEIL, '1'],
+            'ceil negative whole' => ['-1.00', 0, Decimal::ROUND_CEIL, '-1'],
+            'ceil positive' => ['1.5', 0, Decimal::ROUND_CEIL, '2'],
+            'floor small negative' => ['-0.001', 0, Decimal::ROUND_FLOOR, '-1'],
+            'floor zero with decimals' => ['0.00', 0, Decimal::ROUND_FLOOR, '0'],
+            'ceil small positive' => ['0.001', 0, Decimal::ROUND_CEIL, '1'],
+            'ceil zero with decimals' => ['0.00', 0, Decimal::ROUND_CEIL, '0'],
+            'half up negative' => ['-1.005', 2, Decimal::ROUND_HALF_UP, '-1.01'],
+            'half up to zero' => ['-0.004', 2, Decimal::ROUND_HALF_UP, '0.00'],
+        ];
+    }
+
+    /**
+     * @return void
+     */
+    public function testRoundNegativeScale(): void
+    {
+        $this->expectException(InvalidArgumentException::class);
+
+        (new Decimal('15'))->round(-1);
+    }
+
+    /**
+     * @param string $value
+     * @param string $expected
+     *
+     * @return void
+     */
+    #[DataProvider('scientificEdgeProvider')]
+    public function testToScientificEdgeCases(string $value, string $expected): void
+    {
+        $decimal = new Decimal($value);
+        $this->assertSame($expected, $decimal->toScientific());
+        $this->assertSame($value, (string)new Decimal($decimal->toScientific()));
+    }
+
+    /**
+     * @return array
+     */
+    public static function scientificEdgeProvider(): array
+    {
+        return [
+            'zero' => ['0', '0e0'],
+            'zero with scale' => ['0.00', '0.00e0'],
+            'single digit' => ['5', '5.e0'],
+            'power of ten' => ['10', '1.e1'],
+            'large power of ten' => ['100000', '1.e5'],
+            'trailing zero integer' => ['120', '1.2e2'],
+            'trailing zero integer with fraction' => ['120.50', '1.2050e2'],
+            'beyond float precision' => ['1234567890123456789012.5', '1.2345678901234567890125e21'],
+            'beyond int precision' => ['12345678901234567', '1.2345678901234567e16'],
+            'single fraction digit' => ['0.5', '5.e-1'],
+            'small fraction' => ['0.00012', '1.2e-4'],
+            'negative with scale' => ['-12.50', '-1.250e1'],
+        ];
+    }
+
+    /**
+     * @return void
+     */
+    public function testToIntBoundaries(): void
+    {
+        $this->assertSame(PHP_INT_MIN, (new Decimal((string)PHP_INT_MIN))->toInt());
+        $this->assertSame(PHP_INT_MAX, (new Decimal((string)PHP_INT_MAX))->toInt());
+        $this->assertFalse((new Decimal((string)PHP_INT_MIN))->isBigInteger());
+        $this->assertTrue((new Decimal('-9223372036854775809'))->isBigInteger());
+        $this->assertTrue((new Decimal('9223372036854775808'))->isBigInteger());
+    }
+
+    /**
+     * @return void
+     */
+    public function testModOperands(): void
+    {
+        $decimal = new Decimal('10');
+
+        $this->assertSame('0', (string)$decimal->mod('1e1'));
+        $this->assertSame('1', (string)$decimal->mod(new Decimal('3')));
+        $this->assertSame('0.1', (string)$decimal->mod('0.3', 1));
+        $this->assertSame('1.5', (string)(new Decimal('10.5'))->mod('3'));
+    }
+
+    /**
+     * @return void
+     */
+    public function testPowOperands(): void
+    {
+        $decimal = new Decimal('2');
+
+        $this->assertSame('100', (string)(new Decimal('10'))->pow('2e0'));
+        $this->assertSame('4', (string)$decimal->pow(new Decimal('2')));
+        $this->assertSame('0.50', (string)$decimal->pow(-1, 2));
+        $this->assertSame('2.25', (string)(new Decimal('1.50'))->pow(2));
+    }
 }