2 X 1 = 2

2 X 2 = 4

2 X 3 = 6

2 X 4 = 8

2 X 5 = 10

2 X 6 = 12

2 X 7 = 14

2 X 8 = 16

2 X 9 = 18

2 X 10 = 20

2 X 11 = 22

2 X 12 = 24

2 X 13 = 26

2 X 14 = 28

2 X 15 = 30

2 X 16 = 32

2 X 17 = 34

2 X 18 = 36

2 X 19 = 38

2 X 20 = 40