Overview

Calculator evaluates arithmetic expressions with arbitrary-precision decimal math using big.js. It avoids floating-point errors and supports parentheses, operator precedence, and exponents. Use it whenever exact decimal results are required.

How This Skill Works

It parses and evaluates expressions using big.js to ensure exact decimal results. Supported operators include +, -, *, /, ^, and parentheses, with exponentiation treated as right-associative and parentheses taking the highest precedence. It emits errors for common edge cases like empty input, mismatched parentheses, division by zero, or non-integer exponents.

When to Use It

• User asks to calculate or evaluate a math expression
• Precise decimal arithmetic is needed (avoids floating-point errors like 0.1 + 0.2 = 0.30000000000000004)
• Expressions involve parentheses, operator precedence, or exponents
• You need consistent results across repeated calculations
• Working with fractional values where exactness matters

Quick Start

1. Step 1: cd scripts
2. Step 2: npm ci || npm install
3. Step 3: npm run build; npm run calculate "<expression>"

Best Practices

• Use explicit parentheses to enforce grouping and reduce precedence mistakes
• Test with simple, known results (e.g., 3 + 2 → 5) to validate calculations
• Remember exponents must be integers (big.js pow requires integer exponents)
• Be mindful of edge cases: empty expressions, mismatched parentheses, and division by zero
• Prefer decimal inputs over floating literals to ensure consistent results

Example Use Cases

• Input: '3 + 2' → Output: 5
• Input: '10 / 4' → Output: 2.5
• Input: '2 ^ 10' → Output: 1024
• Input: '(2 + 3) * 4' → Output: 20
• Input: '1 + 4.5 * (3-6) / 5' → Output: -1.7

Frequently Asked Questions