40 chairs go in equal rows.
How many ways can you do it?
4 (or 8 turned round)
What goes with 3 to make 21?
3 × ? = 21
7
- Factor
- A number that divides exactly into another number.
- Factor pair
- Two numbers that multiply to make the number.
12 chairs in equal rows.
Each way is a factor pair: 1 × 12, 2 × 6, 3 × 4
4 rows of 3 is 3 rows of 4 turned round.
The pairs meet in the middle, so stop.
Factors of 12: 1, 2, 3, 4, 6, 12
Factors of 12
1 × 122 × 63 × 4
List all the factors of
27
List all the factors of
54
1 × 54 = 54
2 × 27 = 54
3 × 18 = 54
6 × 9 = 54
Factors1, 2, 3, 6, 9, 18, 27, 54
List all the factors of
44
1 × 44 = 44
2 × 22 = 44
4 × 11 = 44
Factors1, 2, 4, 11, 22, 44
List all the factors of
54
1 × 54 = 54
2 × 27 = 54
3 × 18 = 54
6 × 9 = 54
Factors1, 2, 3, 6, 9, 18, 27, 54
List all the factors of
52
1 × 52 = 52
2 × 26 = 52
4 × 13 = 52
Factors1, 2, 4, 13, 26, 52
List all the factors of
54
1 × 54 = 54
2 × 27 = 54
3 × 18 = 54
6 × 9 = 54
Factors1, 2, 3, 6, 9, 18, 27, 54
List all the factors of
60
1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60
List all the factors of
54
1 × 54 = 54
2 × 27 = 54
3 × 18 = 54
6 × 9 = 54
Factors1, 2, 3, 6, 9, 18, 27, 54
List all the factors of
37
1, 37
List all the factors of
54
1 × 54 = 54
2 × 27 = 54
3 × 18 = 54
6 × 9 = 54
Factors1, 2, 3, 6, 9, 18, 27, 54
List all the factors of
75
1, 3, 5, 15, 25, 75
List all the factors of
49
Which number below 30 has the most factors?
24, with eightA number has exactly three factors. What could it be?
4, 9, 25 or 49
40 chairs go in equal rows.
List every way to do it.
1 × 40, 2 × 20, 4 × 10, 5 × 8
List all the factors of 42.
1, 2, 3, 6, 7, 14, 21, 42List all the factors of 81.
1, 3, 9, 27, 81Esme lists the factors of 48 as 1, 2, 3, 4, 6, 8, 12, 24, 48. Which factor has she missed?
16
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