Expert: Steve Holleran - 10/28/2007

Question
I am having difficulty, can you help me?

What do the slashes mean? Also how do I answer the problems correctly?

3/7 + 1/3

7/8 - 4/5

2/8 divided by 6/24

16/21 X 7/8

Answer
Hi Janine,

The slashes are "fraction bars".  When typing, its easier to write the fraction 2
                  -
                  5        as 2/5.

When adding and subtracting, you need to get a common denominator:

3/7 + 1/3 = 9/21 + 7/21 = 16/21

7/8 - 4/5 = 35/40 - 32/40 = 3/40

To divide, multiply by the reciprocal:

2/8 div 6/24 = 2/8 * 24/6 = 48/48 = 1

16/21 * 7/8:  Here, you can reduce by cancelling.  The 8 on the bottom will cancel into the 16, leaving a 1 where the 8 was and a 2 where the 16 was.  Also, the 7 will cancel with the 21, leaving a 1 where the 7 was and a 3 where the 21 was.

So, then you have 2/3 * 1/1 = 2/3

Hope this helps out.
Steve