math
posted by hannah on .
how can you use rounding to estimate 331+193

I'd add 330 and 200. Others might add 330 and 190.

331+193
This depends on whether you're rounding to the nearest 10 or 100. If rounding to the nearest 10, 331 rounds to 330 and 193 rounds to 190, so then you'd do 330+190. If rounding to the nearest 100, 330 rounds to 300 and 190 rounds to 200, so then you'd do 300+200.