Rational subtract

rational-subtract · version 1.0.0 · Numbers & math · free, no key needed

Subtract one rational number from another, given as numerator/denominator integer strings, and return the reduced difference.

Use when you need to: rational subtract · subtract two rational numbers · subtract fractions as rationals.

Supported

• rational subtract
• subtract two rational numbers
• subtract fractions as rationals
• difference of two rationals

Not supported

• rational add
• decimal subtract
• float subtraction
• mixed numbers
• continued fractions
• IEEE-754 arithmetic

Behavior

• Each operand is an object with canonical integer-string numerator and denominator fields.
• The denominator must be a positive canonical integer; zero and negative denominators are rejected.
• Inputs may use -0, which is canonicalized to 0; every other integer must match 0 or -?[1-9][0-9]*.
• The result is a - b, computed as (a.numerator * b.denominator - b.numerator * a.denominator) / (a.denominator * b.denominator).
• The result is reduced by gcd, with the sign only on the numerator; 0 is numerator 0 over denominator 1.
• Input, intermediate, and output numerators and denominators may have at most 1000 digits excluding sign.

Input

• a (object, required)
• b (object, required)

Output

• numerator (string, required)
• denominator (string, required)

Limits

• max digits: 1000

Example

Request input:

{
  "a": {
    "numerator": "1",
    "denominator": "2"
  },
  "b": {
    "numerator": "1",
    "denominator": "3"
  }
}

Response:

{
  "result": {
    "numerator": "1",
    "denominator": "6"
  }
}

How to call it

MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "rational-subtract",
  "version": "1.0.0",
  "input": {
    "a": {
      "numerator": "1",
      "denominator": "2"
    },
    "b": {
      "numerator": "1",
      "denominator": "3"
    }
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/rational-subtract/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"a":{"numerator":"1","denominator":"2"},"b":{"numerator":"1","denominator":"3"}}'

The machine-readable contract is at /v1/tools/rational-subtract/versions/1.0.0.

CLI

node cli.mjs run rational-subtract 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• Rational multiply: Multiply two rational numbers given as numerator/denominator integer strings and return the reduced product.
• Rational add: Add two rational numbers given as numerator/denominator integer strings and return the reduced sum.
• Rational compare: Compare two rational numbers given as numerator/denominator integer strings by exact value.
• Array rational sum: Sum an array of canonical rationals and return the reduced total.
• Array rational mean: Return the reduced arithmetic mean of an array of canonical rationals.
• Array rational min max: Return the reduced numeric minimum and maximum of an array of canonical rationals.