Doubling and
Halving
CATEGORY 1
Doubling and Halving with basic facts.
1 x 16
2 x 8
4 x 4
8 x 2
16 x 1
1 x 36
2 x 18
4 x 9
1 x 20
2 x 10
4 x 5
1 x 24
2 x 12
4 x 6
8 x 3
1 x 48
2 x 24
4 x 12
8 x 6
16 x 3
1 x 40
2 x 20
4 x 10
8 x 5
1 x 12
2 x 6
4 x 3
1 x 32
2 x 16
4 x 8
8 x 4
16 x 2
32 x 1
1 x 56
2 x 28
4 x 14
8 x 7
CATEGORY 2
Doubling and Halving with 1 x 2-digit and 1 x 3-digit numbers.
8 x 16
4 x 32
2 x 64
8 x 32
4 x 64
2 x 168
36 x 5
18 x 10
9 x 20
8 x 125
4 x 250
2 x 500
84 x 5
42 x 10
21 x 20
35 x 8
70 x 4
140 x 2
125 x 8
250 x 4
500 x 2
345 x 8
690 x 4
1380 x 2
8 x 29
4 x 58
2 x 116
CATEGORY 3
Doubling and Halving with 2 x 2-digit numbers.
3 x 60
6 x 30
12 x 15
9 x 56
18 x 28
36 x 14
2 x 280
4 x 140
8 x 70
16 x 35
104 x 3
52 x 6
26 x 12
4 x 120
8 x 60
32 x 15
100 x 4
50 x 8
25 x 16
112 x 2
56 x 4
28 x 8
14 x 16
360 x 3
180 x 6
90 x 12
45 x 24
2 x 1440
4 x 720
8 x 360
16 x 180
32 x 90
64 x 45
CATEGORY 4
For investigation of what happens when you third or triple or
quarter and quadruple numbers.
9 x 12
3 x 36
1 x 108
27 x 15
9 x 45
3 x 135
1 x 405
36 x 18
72 x 9
216 x 3
648 x 1
15 x 16
60 x 4
240 x 1
25 x 48
100 x 12
400 x 3
1200 x 1
64 x 35
16 x 140
4 x 560
1 x 2240
18 x 12
9 x 24
4.5 x 36
2.25 x 72
6 x 12
3 x 24
1.5 x 48
6 x 24
3 x 48
1.5 x 96

Doubling and halving with multiplication