Divisibility Calculator

How it works

1. 1Enter any integer a and a non-zero divisor b. The calculator truncates both values to whole numbers before dividing.
2. 2It computes the remainder using the modulo operation (a % b). If the remainder is 0, a is exactly divisible by b.
3. 3The quotient (how many times b fits into a) and the remainder are shown alongside the yes/no divisibility result.

Use cases

• Quickly verify divisibility rules in mental-math practice — e.g. confirming a number is divisible by 9 because its digit sum is a multiple of 9.
• Check whether a batch size, page count, or group size divides evenly so you can plan without leftovers.
• Validate modular-arithmetic steps when working through number-theory problems or competitive-programming exercises.

Frequently asked questions

What are the most common divisibility rules?

A number is divisible by 2 if its last digit is even; by 5 if it ends in 0 or 5; by 10 if it ends in 0. It’s divisible by 3 (or 9) if the sum of its digits is a multiple of 3 (or 9). These shortcuts let you test small divisors mentally.

What happens when the divisor is 0?

Division by zero is undefined. The calculator returns — for both the quotient and remainder, and marks the number as not divisible.

Does this work with negative numbers?

Yes. Both a and b are truncated to integers and the standard signed modulo is applied. For example, −7 ÷ 3 gives quotient −2 and remainder −1.