Modulo Calculator

Calculate modulo operations (remainder after division) with step-by-step explanations

Calculate Modulo Operation

The number being divided

The number dividing (must be non-zero)

Clock Arithmetic Example

🕚 Time Calculation

Current time: 11:00 PM

Sleep duration: 8 hours

Calculation: (11 + 8) mod 12 = 19 mod 12 = 7

Wake up time: 7:00 AM 🕖

🍕 Pizza Sharing

Total slices: 10

People: 3

Calculation: 10 mod 3 = 1

Each person gets: 3 slices, 1 slice left over

Common Modulo Results

10 mod 31
17 mod 52
25 mod 74
100 mod 111
256 mod 160

Modulo Properties

x mod y is always between 0 and y-1

If x < y, then x mod y = x

x mod 1 is always 0

Even numbers: x mod 2 = 0

Odd numbers: x mod 2 = 1

Modulo in Programming

Python: a % b
JavaScript: a % b
Java: a % b
C++: a % b
Math: a mod b

Understanding Modulo Operations

What is Modulo?

The modulo operation finds the remainder after division of one number by another. When we write "x mod y = r", we're saying that x divided by y leaves a remainder of r.

Mathematical Definition

x = q x y + r

where 0 ≤ r < |y|

  • x: dividend (number being divided)
  • y: divisor (number dividing by)
  • q: quotient (whole number result)
  • r: remainder (modulo result)

Real-World Applications

  • Time calculations: 12-hour and 24-hour formats
  • Cryptography: RSA encryption and hash functions
  • Check digits: ISBN, credit card validation
  • Computer graphics: Texture wrapping and animations
  • Data structures: Hash tables and circular arrays

Modular Congruence

a ≡ b (mod n)

"a is congruent to b modulo n"

This means a and b have the same remainder when divided by n

Modular Arithmetic Rules

Addition

(a + b) mod n =

((a mod n) + (b mod n)) mod n

Multiplication

(a x b) mod n =

((a mod n) x (b mod n)) mod n

Exponentiation

a^b mod n =

((a mod n)^b) mod n