Lowest common multiple

The Maths Habit

Pip and Tad hop along the stones. Which stone do they both land on first?

PipTadThe sixth stone

What comes next?

3, 6, 9,12
4, 8,12
5, 10, 15,20

Multiple
A number in a times table.
1234567891011121314151617181920
Common multiple
A number in both times tables.
1234567891011121314151617181920
Lowest common multiple (LCM)
The smallest number in both times tables.
1234567891011121314151617181920

Number the stones. Put them in rows of ten.

1234567891011121314151617181920
  1. 1Pip lands on 2, 4, 6, 8 ...The multiples of 2.
  2. 2Tad lands on 3, 6, 9, 12 ...The multiples of 3.
  3. 3They both land on 6 first.6 is the lowest common multiple of 2 and 3.

1234567891011121314151617181920
1Multiples of 224681012
2Multiples of 3369121518
3LCM = 6
  1. 1Count up in the first number.Shade them on the grid. Write them in the boxes.
  2. 2Count up in the second number.Ring them on the grid. Write them in the boxes.
  3. 3Find the first number in both.That is the lowest common multiple.

Find the lowest common multiple of 4 and 6.

1234567891011121314151617181920
1Multiples of 448121620
2Multiples of 661218
3LCM = 12

Find the lowest common multiple of 5 and 4.

1234567891011121314151617181920
1Multiples of 55101520
2Multiples of 448121620
3LCM = 20

Find the lowest common multiple of 4 and 6.

1234567891011121314151617181920
1Multiples of 448121620
2Multiples of 661218
3LCM = 12
1Count up in the first number.2Count up in the second number.3Find the first number in both.

Find the lowest common multiple of 5 and 2.

1234567891011121314151617181920
1Multiples of 55101520
2Multiples of 224681012
3LCM = 10

Find the lowest common multiple of 4 and 6.

1234567891011121314151617181920
1Multiples of 448121620
2Multiples of 661218
3LCM = 12
1Count up in the first number.2Count up in the second number.3Find the first number in both.

Find the lowest common multiple of 6 and 10.

123456789101112131415161718192021222324252627282930
1Multiples of 6612182430
2Multiples of 10102030
3LCM = 30

Find the lowest common multiple of 4 and 6.

1234567891011121314151617181920
1Multiples of 448121620
2Multiples of 661218
3LCM = 12
1Count up in the first number.2Count up in the second number.3Find the first number in both.

Find the lowest common multiple of 9 and 3.

1234567891011121314151617181920
1Multiples of 9918
2Multiples of 3369121518
3LCM = 9

1Count up in the first number.2Count up in the second number.3Find the first number in both.

1Find the lowest common multiple of 2 and 6.

1234567891011121314151617181920
Multiples of 224681012
Multiples of 661218
LCM = 6

2Find the lowest common multiple of 10 and 4.

1234567891011121314151617181920
Multiples of 101020
Multiples of 448121620
LCM = 20

3Find the lowest common multiple of 8 and 6.

123456789101112131415161718192021222324252627282930
Multiples of 881624
Multiples of 6612182430
LCM = 24

A story wants the lowest common multiple when it asks for

the same number of each,

together again.

Pip hops 3 stones at a time. Tad hops 4 stones at a time. Which stone do they both land on first?

1234567891011121314151617181920
1Pip369121518
2Tad48121620
3Stone 12

Red bricks are 2 cm tall. Blue bricks are 5 cm tall. A red tower and a blue tower are the same height. What is the smallest height?

1234567891011121314151617181920
1Red tower24681012
2Blue tower5101520
310 cm

Pip hops 3 stones at a time. Tad hops 4 stones at a time. Which stone do they both land on first?

1234567891011121314151617181920
1Pip369121518
2Tad48121620
3Stone 12
1Count up in the first number.2Count up in the second number.3Find the first number in both.

A bell rings every 6 minutes. A buzzer goes every 4 minutes. They go together now. When do they next go together?

1234567891011121314151617181920
1Bell61218
2Buzzer48121620
3In 12 minutes

Pip hops 3 stones at a time. Tad hops 4 stones at a time. Which stone do they both land on first?

1234567891011121314151617181920
1Pip369121518
2Tad48121620
3Stone 12
1Count up in the first number.2Count up in the second number.3Find the first number in both.

Ali runs a lap in 3 minutes. Ben runs a lap in 5 minutes. They start together. When are they next at the start together?

1234567891011121314151617181920
1Ali369121518
2Ben5101520
3In 15 minutes

Pip hops 3 stones at a time. Tad hops 4 stones at a time. Which stone do they both land on first?

1234567891011121314151617181920
1Pip369121518
2Tad48121620
3Stone 12
1Count up in the first number.2Count up in the second number.3Find the first number in both.

Red beads come in bags of 6. Blue beads come in bags of 9. Zoe buys the same number of each. What is the least number of red beads she can buy?

1234567891011121314151617181920
1Red beads61218
2Blue beads918
318 beads

Lowest common multiple worksheet, page 1

Lowest common multiple worksheet, page 2

Answer sheet

Is it right?
Thumbs up: right. Thumbs down: wrong.

  1. 12 is a multiple of 4

    Right

  2. The LCM of 2 and 5 is 10

    Right

  3. 3 is a multiple of 12

    Wrong: 12 is a multiple of 3

  4. The LCM of 4 and 8 is 32

    Wrong: it is 8

  5. 20 is a common multiple of 4 and 5

    Right

  1. Find the lowest common multiple of 12 and 15.

    60

  2. The lowest common multiple of 6 and a number is 24. What could the number be?

    8 or 24

  3. Find the lowest common multiple of 2, 3 and 5.

    30

  1. Find the LCM of 4 and 3.

    12
    1Count up in thefirst number.481216202Count up in thesecond number.3Find the firstnumber in both.LCM =

  2. Find the LCM of 8 and 6.

    24
    1Count up in thefirst number.2Count up in thesecond number.3Find the firstnumber in both.LCM =

  3. Find the lowest common multiple of 10 and 4.

    20
Exit tickets to print