Question

select any strategy that can be used to add 62 + 21. choose all answers that apply; a add 62 + 1 then add 20. b add 60 + 20 then add 21.

Explanation:

• For option A: We can break down 21 into 1 + 20. So, \(62 + 21=62+(1 + 20)=(62 + 1)+20\), which means adding 62 + 1 then adding 20 is a valid strategy.
• For option B: If we add 60+20 first, we get 80, but then adding 21 would give \(80 + 21=101\), while \(62+21 = 83\). The correct breakdown for this kind of strategy would be \(62+21=(60 + 2)+(20+1)=(60 + 20)+(2 + 1)=80 + 3=83\), so adding 60 + 20 then adding 21 is incorrect.

Answer:

A. Add 62 + 1 then add 20.