calculator
// Performs arbitrary-precision arithmetic calculations including addition, subtraction, multiplication, division, and exponents. Use when the user asks to calculate, compute, or evaluate math expressions, or when precise decimal arithmetic is needed to avoid floating-point errors.
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updated:January 11, 2026
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SKILL.md Frontmatter
namecalculator
descriptionPerforms arbitrary-precision arithmetic calculations including addition, subtraction, multiplication, division, and exponents. Use when the user asks to calculate, compute, or evaluate math expressions, or when precise decimal arithmetic is needed to avoid floating-point errors.
licenseMIT
compatibilityRequires Node.js and npm
metadata[object Object]
Calculator
Evaluate arithmetic expressions with arbitrary-precision decimal math using big.js.
When to Use
- 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
Supported Operations
| Operator | Description | Precedence |
|---|---|---|
+ | Addition | 1 |
- | Subtraction | 1 |
* | Multiplication | 2 |
/ | Division | 2 |
^ | Exponent (right-associative) | 3 |
() | Parentheses | Highest |
Usage
cd scripts
npm ci || npm install
npm run build
npm run calculate "<expression>"
Examples
| Input | Output |
|---|---|
"3 + 2" | 5 |
"10 / 4" | 2.5 |
"2 ^ 10" | 1024 |
"(2 + 3) * 4" | 20 |
"1 + 4.5 * (3-6) / 5" | -1.7 |
"-5 + 3" | -2 |
"2 ^ 3 ^ 2" | 512 (right-associative: 2^9) |
Edge Cases
- Empty expression: Throws "Empty expression" error
- Mismatched parentheses: Throws "Mismatched parentheses" error
- Division by zero: big.js throws an error
- Exponent must be integer: big.js
.pow()requires integer exponents
Limitations
- No trigonometric functions (sin, cos, tan)
- No variables or symbolic math
- Exponents must be integers
- No factorial, modulo, or bitwise operators