### SKills Post 2

Friday, April 17, 2009
Sometimes when subtracting fraction you first have to turn them into improper factions, you can also borrow from the fractions.

A good time to switch to improper factions first is when you find out you can't subtract the numerators and the fractions are small. ,
2 1/2 - 1 3/4 =
2 2/4 - 1 3/4 =
= ?

You can't subtract 3 from 2 so you have to start the question with improper factions,
2 1/2 - 1 3/4 =
5/2 - 7/4 =
10/4 - 7/4
=3/4
These questions are an example of when you need to do switch to start with improper fractions.

A good time to borrow when subtracting fractions is when the fraction are huge,
625 1/2 - 100 3/4 =
625 2/4 - 100 3/4 =
= ?

When the question ends up with 2 subtracted by 3 is a good time to borrow,
625 1/2 - 100 3/4 =
625 2/4 - 100 3/4 =
(624 + 4/4 + 2/4)
624 6/4 - 100 3/4=
= 624 9/4
The question is now solved by borrowing fractions.

You can do any subtracting question now, you can do it normally, you can borrow, or you can use improper fractions