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Modulus

The modulus operation finds the remainder when one number is divided by another. It’s often shown using the percent symbol: %

Modulus code example

# Use modulus to find out how many people won't fit on the last bus
people = 53
bus_capacity = 20

left_behind = people % bus_capacity
print("People left behind:", left_behind)


	
number = 9

# Check if the number is even by seeing if the remainder when divided by 2 is 0
if number % 2 == 0:
    print("Even number")
else:
    print("Odd number")

Modulus common uses

  • Finding Remainders
    • When dividing things into groups
    • Example: 53 % 20 → 13 people don’t fit on a full bus of 20
  • Checking Even or Odd Numbers
    • If a number % 2 is 0, it’s even
    • If it’s not 0, it’s odd
  • Checking Multiples
    • See if one number is a multiple of another
    • Example: If number % 4 == 0 → multiple of 4!