Question

Donte used mental math to find the exact sum of 386 and 14. Which strategy could Donte have used?

380 + 6 + 14

380 + 14 + 14

386 + 10 + 4 + 14

386 + 14 + 80 + 6

Answer 1

380 + 6 + 14

Explanation:

Answer 2

380 + 6 + 14

Explanation:

The sum of 386 and 14 is 386 + 14 = 400.

To find which stategy he used, we find the results of each sum, and it has to be 400.

380 + 6 + 14

380 + 6 + 14 = 386 + 14 = 400

So this is the strategy that he could have used.

380 + 14 + 14

380 + 14 + 14 = 394 + 14 = 408

Result different of 400, which means that this was not the strategy

386 + 10 + 4 + 14

386 + 10 + 4 + 14 = 386 + 14 + 14 = 408

Result different of 400, which means that this was not the strategy

386 + 14 + 80 + 6

386 + 14 + 80 + 6 = 400 + 86 = 486

Result different of 400, which means that this was not the strategy