Expert: Abe Mantell - 6/9/2009

Question
I am trying to figure how to solve decimals with nothing to borrow from.  Ex... 0.0025 - 0.075, 0.9- 76.78, 6.241 - 37.7293.  I have seen the answers and used a calculator but, I don't understand how 0.0025- 0.075= 0.075. I saw one website that renamed the first zero with a 7 on several problems.  Why would you do that? Please help. How do you subtract decimals with nothing to borrow from?


Answer
How did you get 0.0025 - 0.075 = 0.075 ???
It should be -0.0725

When you subtract a larger number from a smaller one, you find the
difference (by switching the order so it is the smaller subtracted
from the larger), but just out a negative sign in front of the answer.
For example, 3-8=-(8-3)=-5...so 0.0025-0.075=-(0.075-0.0025)=-0.0725

OK?  I hope this helps.

Abe