This is how we write numbers from 1 to 10.

1    one

2    two

3    three

4    four

5    five

6    six

7    seven

8    eight

9    nine

10  ten

This is how we write numbers from 11 to 20.

11   eleven

12   twelve

13   thirteen

14   fourteen

15   fifteen

16   sixteen

17   seventeen

18   eighteen

19   nineteen

20   twenty