Rule of 12

There is no set rule for the 12s other than PRACTICE!
A tip might be to add ten to each number and then two
so 12 x 2 would be 12 (from 12x1 = 12) 
                plus 10 = 22 
                plus 2 = 24
1x12 = 12 
2x12 = 24
3x12 = 36
4x12 = 48
5x12 = 60
6x12 = 72
7x12 = 84
8x12 = 96
9x12 = 108
10x12 = 120
11x12 = 132
12x12 = 144

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