Question

Jada says she can find 87-59 by taking away 60 and adding 1 so it is the same as 27+1 or 28. Explain why jadas method to calculate 87-59 makes sense.

Answer 1

The correct answer is 28.

Explanation:

Actually Jada makes problem simpler by adding and subtracting 1

that is

87 ₋ 59 ₋1 ₊ 1

so there would be no effect on our final answer because we have added 1 and also subtracted 1

Now,

87 - 59 -1 + 1

87 - 60 +1 ( ∵ -59 - 1 = -60 )

27 + 1 (∵ 87 - 60 = 27 )

28

so the final answer is 28 .