This activity is about finding common multiples of numbers within a given range.

Example

Write down two numbers between 20 and 40 that are multiples of both 3 and 4.

Answer

The multiples of 3 are 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39... etc.

The multiples of 4 are 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52... etc.

The common multiples are the ones that appear in both lists and are shown in red.

The ones in the range between 20 and 40 are 24 and 36.