SUBTRACTION.
16. How many are 10 less 8? 10 less 77 10 less 5? 10 less 3? 10 less 1?
17. How many are 11 less 9? 11 less 7? 11 less 5? 11 less 3? 11 less 4 ?
18. How many are 12 less 10? 12 less 8% 12 less 6? 12 less 4? 12 less 7?
19. How many are 13 less 11P 13 less 10? 13 less 7? 13 less 9? 13 less 5?
20. How many are 14 legs 119 14 less 9? 14 less 8? 14 less 6? 14 less 7? 14 less 3
21. How many are 15 less 2? 15 less 49 15 less 5? 15 less 7? 15 less 9? 15 less 13?
22. How many are 16 less 3? 18 less 4? 16 less 7? 16 less 9 ? 16 less 11? 16 less 15?
23. How many are 17 less 1? 17 less 3? 17 less 5? 17 less 7? 17 less 8? 17 less 12?
24. How many are 18 less 2? 18 less 4? 18 less 7? 18 less 8? 18 less 10? 18 less 12
25. How many are 19 less 1? 19 less 37 19 less 5? 19 less 72 19 less 9? 19 less 16?
26. How many are 20 less 5 ? 20 less 8? 20 less 9? 20 less 122 20 less 15? 20 less 19?
27. Bought a horse for 60 dollars, and sold him for 90 dollars; how much did I gain?
ILLUSTRATION.—60 equals 6. tens, and 90 equals 9 tens; 6 tens from 9 tens leave 3 tens, or 30. Therefore I gained 30 dollars.
28. Sold a wagon for 70 dollars which cost me 100 dollars; how much did I lose?
29. John travels 30 miles a day, and Samuel 90 miles; what is the difference?
30. I have 100 dollars, and after I shall have given 20 to Benjamin, and paid a debt of 30 dollars to John Smith, how many dollars have I left?
