Question

What is front-end estimation and how does it work?

Answer 1

The front-end estimation is a way to find the estimation of sums by rounded where you add the units and the decimal parts independently. For example

4.9 + 5.8

First, add the units, so

4 + 5 = 9

Then, the sum of the decimal parts are:

0.9 + 0.8

But 0.9 and 0.8 are closer to 1, so we can add them as:

1 + 1 = 2

Finally, the approximated answer will be:

9 + 2 = 11

This is not the exact answer but it is a good approximation.