Quick guide
How to use this calculator
- Enter two signed integers.
- Choose addition, subtraction, multiplication, or division.
- Read the exact integer or reduced fraction.
- Review the sign rule displayed with the result.
Calculation method
Signed-number rules made explicit
Addition and subtraction compare signs and magnitudes; subtraction can be understood as adding the opposite.
For multiplication and division, matching signs produce a positive result and different signs produce a negative result. Non-integral division remains an exact reduced fraction.
Worked example
Divide −21 by 6
Different signs give a negative result. Reducing the fraction by the common factor three gives the exact quotient.
−21 ÷ 6 = −21/6 = −7/2
Supported inputs
Precision and limits
Signed integers
Each input may have an optional leading + or − sign and up to 1,000 digits.
Four operations
Addition, subtraction, multiplication, and division are supported.
Exact division
Non-integral quotients remain reduced fractions with a decimal representation.
Undefined state
Division by zero is rejected rather than displayed as Infinity.