The document shows a series of addition problems where 1 is added to incrementing numbers on each line. The problems are grouped so that the sums are the same within each group, with the sums increasing with each new group.

1. 1 + 8 = 1 + 5 = 1 + 3 =

2. 1 + 0 = 1 + 1 = 1 + 2 =

3. 1 + 0 = 1 + 1 = 1 + 2 =

4. 1 + 3 = 1 + 4 = 1 + 5 =

5. 1 + 3 = 1 + 4 = 1 + 5 =

6. 1 + 6 = 1 + 7 = 1 + 8 =

7. 1 + 6 = 1 + 7 = 1 + 8 =

8. 1 + 9 = 1 + 10 = 1 + 11 =

9. 1 + 9 = 1 + 10 = 1 + 11 =