Reasoning : When you estimate to determine if you have enough money , why should you underestimate the amount you have?

Help!!!!

3 answers

What do you think?
should you underestimate so that if you dont have enough you should just underestimate just incase? like you wanna spend 6.00 but you dont know know how much you have so you get stuff that are below it?? if that makes sense
Yes, you're right.