Listing factors

The Maths Habit

Which chairs are in equal rows?

A
✓ Equal rowsB
Not equalC
✓ Equal rows

What goes in the box?

2 × = 147
3 × = 10It does not go
5 × = 204

Equal rows
Rows that all have the same number of things.
Factor
A number that divides exactly into another number.
Factor pair
Two numbers that multiply to make the number.

12 chairs go in equal rows. Each way is a factor pair.

  1. 1 row of 121 × 12
  2. 2 rows of 62 × 6
  3. 3 rows of 43 × 4
  4. 4 rows of 3STOP3 rows of 4 turned round

1×pair= number2×pair= number3×✗= number4×pair= numberSTOPtry
  1. 1Try 1, 2, 3 ... in order.Write the pair. Write ✗ if it does not go.
  2. 2Stop when a pair turns round.You have that pair already, the other way round.

Write all the factor pairs of 18.

1Try 1, 2, 3 ... in order.
2Stop when a pair turns round.
1×18= 18
2×9= 18
3×6= 18
4×✗= 18
5×✗= 18
6×3= 18STOP

Write all the factor pairs of 10.

1Try 1, 2, 3 ... in order.
2Stop when a pair turns round.
1×10= 10
2×5= 10
3×✗= 10
4×✗= 10
5×2= 10STOP

Write all the factor pairs of 18.

1Try 1, 2, 3 ... in order.
2Stop when a pair turns round.
1×18= 18
2×9= 18
3×6= 18
4×✗= 18
5×✗= 18
6×3= 18STOP
1Try 1, 2, 3 ... in order.2Stop when a pair turns round.

Write all the factor pairs of 8.

1Try 1, 2, 3 ... in order.
2Stop when a pair turns round.
1×8= 8
2×4= 8
3×✗= 8
4×2= 8STOP

Write all the factor pairs of 18.

1Try 1, 2, 3 ... in order.
2Stop when a pair turns round.
1×18= 18
2×9= 18
3×6= 18
4×✗= 18
5×✗= 18
6×3= 18STOP
1Try 1, 2, 3 ... in order.2Stop when a pair turns round.

Write all the factor pairs of 20.

1Try 1, 2, 3 ... in order.
2Stop when a pair turns round.
1×20= 20
2×10= 20
3×✗= 20
4×5= 20
5×4= 20STOP

Write all the factor pairs of 18.

1Try 1, 2, 3 ... in order.
2Stop when a pair turns round.
1×18= 18
2×9= 18
3×6= 18
4×✗= 18
5×✗= 18
6×3= 18STOP
1Try 1, 2, 3 ... in order.2Stop when a pair turns round.

Write all the factor pairs of 15.

1Try 1, 2, 3 ... in order.
2Stop when a pair turns round.
1×15= 15
2×✗= 15
3×5= 15
4×✗= 15
5×3= 15STOP

1Try 1, 2, 3 ... in order.2Stop when a pair turns round.

1Write all the factor pairs of 6.

1×6= 6
2×3= 6
3×2= 6STOP

2Write all the factor pairs of 24.

1×24= 24
2×12= 24
3×8= 24
4×6= 24
5×✗= 24
6×4= 24STOP

3Write all the factor pairs of 30.

1×30= 30
2×15= 30
3×10= 30
4×✗= 30
5×6= 30
6×5= 30STOP

1×pair= number2×pair= number3×✗= number4×pair= numberSTOPtry
  1. 1Try 1, 2, 3 ... in order.Write the pair. Write ✗ if it does not go.
  2. 2Stop when a pair turns round.You have that pair already, the other way round.
  3. 3List the factors in order.Down the left. Then up the right.

List all the factors of 28.

1Try 1, 2, 3 ... in order.
2Stop when a pair turns round.
1×28= 28
2×14= 28
3×✗= 28
4×7= 28
5×✗= 28
6×✗= 28
7×4= 28STOP
3List the factors in order.
12471428

List all the factors of 30.

1Try 1, 2, 3 ... in order.
2Stop when a pair turns round.
1×30= 30
2×15= 30
3×10= 30
4×✗= 30
5×6= 30
6×5= 30STOP
3List the factors in order.
12356101530

List all the factors of 28.

1Try 1, 2, 3 ... in order.
2Stop when a pair turns round.
1×28= 28
2×14= 28
3×✗= 28
4×7= 28
5×✗= 28
6×✗= 28
7×4= 28STOP
3List the factors in order.
12471428
1Try 1, 2, 3 ... in order.2Stop when a pair turns round.3List the factors in order.

List all the factors of 12.

1Try 1, 2, 3 ... in order.
2Stop when a pair turns round.
1×12= 12
2×6= 12
3×4= 12
4×3= 12STOP
3List the factors in order.
1234612

List all the factors of 28.

1Try 1, 2, 3 ... in order.
2Stop when a pair turns round.
1×28= 28
2×14= 28
3×✗= 28
4×7= 28
5×✗= 28
6×✗= 28
7×4= 28STOP
3List the factors in order.
12471428
1Try 1, 2, 3 ... in order.2Stop when a pair turns round.3List the factors in order.

List all the factors of 14.

1Try 1, 2, 3 ... in order.
2Stop when a pair turns round.
1×14= 14
2×7= 14
3×✗= 14
4×✗= 14
5×✗= 14
6×✗= 14
7×2= 14STOP
3List the factors in order.
12714

List all the factors of 28.

1Try 1, 2, 3 ... in order.
2Stop when a pair turns round.
1×28= 28
2×14= 28
3×✗= 28
4×7= 28
5×✗= 28
6×✗= 28
7×4= 28STOP
3List the factors in order.
12471428
1Try 1, 2, 3 ... in order.2Stop when a pair turns round.3List the factors in order.

List all the factors of 35.

1Try 1, 2, 3 ... in order.
2Stop when a pair turns round.
1×35= 35
2×✗= 35
3×✗= 35
4×✗= 35
5×7= 35
6×✗= 35
7×5= 35STOP
3List the factors in order.
15735

Listing factors worksheet, page 1

Listing factors worksheet, page 2

Answer sheet

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

  1. The factors of 10 are 1, 2, 5, 10

    Right

  2. The factors of 12 are 2, 3, 4, 6

    Wrong: 1 and 12 are missing

  3. 4 is a factor of 18

    Wrong: 4 does not go into 18

  4. The factors of 15 are 1, 3, 5, 15

    Right

  5. 7 is a factor of 21

    Right

  1. Which number less than 20 has the most factors?

    12 and 18

  2. A number has exactly two factors. One of them is 13. What is the number?

    13

  3. List all the factors of 36.

    1, 2, 3, 4, 6, 9, 12, 18, 36

  1. List all the factors of 6.

    1, 2, 3, 6
    1×= 62×= 63×= 6STOP1Try 1, 2, 3 ...in order.2Stop when a pairturns round.3List the factorsin order.

  2. List all the factors of 20.

    1, 2, 4, 5, 10, 20
    ×= 20×= 20×= 20×= 20×= 20STOP1Try 1, 2, 3 ...in order.2Stop when a pairturns round.3List the factorsin order.

  3. List all the factors of 32.

    1, 2, 4, 8, 16, 32
Exit tickets to print