Since we can add a number to a tens number easily, we make one of the addends a tens number when solving an addition problem.
Example 1:
Add 9 and 6.
9 + 6 = 9 + (1 + 5)
= (9 + 1) + 5
= 10 + 5 = 15
Note that adding 10 and 5 is much easier than adding 9 and 6.
Example 2:
Add 18 and 16.
18 + 16 = 18 + (2 + 14)
= (18 + 2) + 14
= 20 + 14 = 34
Note that adding 20 and 14 is much easier than adding 18 and 16.
Answer:
well if we are going by pattern them possibly 20 or 30 im sorry if its wrong i just need more info on how i should answer it
Step-by-step explanation:
