Question

Use benchmarks to estimate 2.81 + 3.72

Answer 1

I am guessing it's seven because 2.81 rounds to 3 and 3.72 rounds to 4. So 3+4=7

Answer 2

because 2.81 rounded to the nearest benchmark is 3, and 3.72 rounded to the nearest benchmark is 3.5, and 3 plus 3.5 is 6.5