Use rounding or compatible numbers to estimate the sum 271 + 425

So, to do this we'll be using rounding instead of compatible to estimate.

To begin, do 271 + 425

By rounding a hundred, you would do

300 + 400 = 700 as the estimated sum.

By rounding tens, you would do

270 + 430 = 700 as estimated sum.

In this case, either one can be done which means 700 is the best estimated sum.