One and ten is eleven.

1 + 10 = 11

10 + 1 = 11

Two and ten is twelve.

2 + 10 = 12

10 + 2 = 12

Three and ten is thirteen.

3 + 10 = 13

10 + 3 = 13

Four and ten is fourteen.

4 + 10 = 14

Five and ten is fifteen.

5 + 10 = 15

Six and ten is sixteen.

6 + 10 = 16

Seven and ten is seventeen.

7 + 10 = 17

Eight and ten is eighteen.

8 + 10 = 18

10 + 8 = 18

Nine and ten is nineteen.

9 + 10 = 19

10 + 9 = 19

Ten and ten is twenty.

Two tens are twenty.

10 + 10 = 20