Question

Ned estimates that `17/4` is close to `4.25`. Is this a good estimate?

Answer 1

`17` is a little bigger than `16`, so Ned's answer of `4.25`, which is a little bigger than `4`, is reasonable, because we know `16-:4=4`.

Explanation:

Estimation involves doing an easier calculation than the one required.

`17-:4` is tough to do in your head, but `16-:4` is pretty easy.

We know the answer to that is `4`, and `17` is a little bit bigger than `16`, so an answer a little bit bigger than `4` is reasonable.

So, even if `4.25` is not the exact answer (in this case it is), it's a reasonable answer. It makes sense. It's plausible.