writing in math- explain how you can estimate to tell whether 433-147=286 is reasonable.?

Question

my son's 3rd grade math homework? My dh and I can't agree. I think the answer needs to be in words, he says just estimate the numbers to answer....

Answer 1

Just round the 433 up to 450, the 147 to 150, and the 286 to 300. All you should need to write is:
450-150=300

Answer 2

If the assignment is "to explain", then I agree that you need to tell in words what you do to estimate.

I had a hard time with estimating...it seemed just as simple to do the math!

But I'd think throught it this way...400 minus 150 is 250, plus about 30 from the 433 is 280. To me, that's an estimate, so yes, it would be reasonable.

Third grade must be harder than it was in 1959.

Answer 3

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