Here one addend exceeds the other by 1.
5. Subtract:
-2 -3 -4 -5 -6 -7 -8 -9 -10
-1 -2 -3 -4 -5 -6 -7 -8 1-9
Here the minuend is one greater in each case.
6. Teach the parts of 10.
+5 +2 +3 +4 +9
+5 +8 +7 +6 +1
7. In adding 9 to numbers have the child think of 9 as 10,
thus 9+6 = 10+5 and 9+8 = 10+7
8. Teach the corresponding subtractions.
9. Add 8 to each number up to 10.