You must do this without the use of a calculator. If you give 8498 which is what you get using a calculator, I would guess that you would be marked wrong.
If you can add 48 + 37 in your head, that would be a pretty good estimate.
Those two numbers added together give 85, so the answer to the estimate would be 8500. That's what I would expect to see if I asked the question.
If you can't do that in your head, try 5 + 4 which gives you 9. So you would give 5000 + 4000 as your estimate which is 9000. That also would be acceptable if I gave out the question.
