1.
Count backwards by 2s: 12, ___, 8, 6, 4, 2
2.
Count backwards by 2s: 12, ___, 8, 6, 4, 2
3.
Count backwards by 3s: 24, 21, 18, ___, 12, 9
4.
Count backwards by 3s: 18, 15, 12, ___, 6, 3
5.
Count backwards by 3s: 15, 12, 9, ___, 3, 0
6.
Count backwards by 3s: 18, 15, 12, 9, ___, 3
7.
Count backwards by 3s: 24, 21, 18, ___, 12, 9
8.
Count backwards by 3s: 27, 24, ___, 18, 15, 12
9.
Count backwards by 2s: 10, 8, 6, 4, ___, 0
10.
Count backwards by 3s: 24, ___, 18, 15, 12, 9
11.
Count backwards by 2s: 12, ___, 8, 6, 4, 2
12.
Count backwards by 2s: 18, 16, 14, 12, ___, 8
13.
Count backwards by 3s: 24, 21, ___, 15, 12, 9
14.
Count backwards by 3s: 18, 15, ___, 9, 6, 3
15.
Count backwards by 2s: 16, ___, 12, 10, 8, 6
16.
Count backwards by 2s: 18, 16, 14, 12, ___, 8
17.
Count backwards by 2s: 12, 10, 8, ___, 4, 2
18.
Count backwards by 2s: 12, 10, 8, 6, ___, 2
19.
Count backwards by 2s: 14, 12, 10, ___, 6, 4
20.
Count backwards by 3s: 24, ___, 18, 15, 12, 9