1.
Count backwards by 2s: 10, 8, 6, ___, 2, 0
2.
Count backwards by 2s: 14, 12, 10, ___, 6, 4
3.
Count backwards by 2s: 16, 14, ___, 10, 8, 6
4.
Count backwards by 8s: 48, 40, 32, 24, ___, 8
5.
Count backwards by 7s: 56, 49, 42, ___, 28, 21
6.
Count backwards by 3s: 18, ___, 12, 9, 6, 3
7.
Count backwards by 7s: 42, ___, 28, 21, 14, 7
8.
Count backwards by 5s: 45, ___, 35, 30, 25, 20
9.
Count backwards by 7s: 56, 49, 42, ___, 28, 21
10.
Count backwards by 8s: 56, 48, ___, 32, 24, 16
11.
Count backwards by 2s: 18, 16, 14, 12, ___, 8
12.
Count backwards by 6s: 42, 36, 30, ___, 18, 12
13.
Count backwards by 5s: 40, ___, 30, 25, 20, 15
14.
Count backwards by 8s: 40, 32, 24, ___, 8, 0
15.
Count backwards by 3s: 15, 12, ___, 6, 3, 0
16.
Count backwards by 4s: 20, 16, 12, 8, ___, 0
17.
Count backwards by 7s: 56, ___, 42, 35, 28, 21
18.
Count backwards by 9s: 72, 63, 54, 45, ___, 27
19.
Count backwards by 3s: 21, 18, 15, ___, 9, 6
20.
Count backwards by 3s: 21, 18, 15, 12, ___, 6