The Math Meridian
Back to Grade 5

Factors and divisibility

Questions at easy, medium and hard levels. Pick a level and get a fresh set every time, with instant feedback.

Learn it Find factors in pairs. To count numbers divisible by a OR b, add the two counts and subtract the numbers divisible by both (by their LCM), so they aren't counted twice.

Example: How many numbers from 1 to 60 are divisible by 4 or 6?

  1. By 4: $60 \div 4 = 15$. By 6: $60 \div 6 = 10$.
  2. By both (by LCM 12): $60 \div 12 = 5$.
  3. $15 + 10 - 5 = 20$.

Loading questions…