Fraction Slide Rule
 

B

A

 

Use the fraction slide ruler to learn about the addition and subtraction of fractions.    

Adding fractions ... to add fractions A and B on the slide rule.    (A + B)

Place the ZERO of the top ruler over the fraction "A"  on the bottom ruler.
Look along the top ruler to the fraction "B"   
On the bottom ruler, read the fraction under the fraction "B" of the top ruler.  This fraction will be the answer to the addition problem.

Example:

1/4 + 9/16 = 13/16

Subtracting fractions ... to subtract fractions B from A on the slide rule.    (A - B)

Find fraction "B" on the top ruler.
Find fraction "A" on the bottom ruler.
Line top and bottom rulers so that the number being subtracted are one on top of the other.
Look on the bottom ruler,  below the ZERO on the top ruler ... and read the fraction on the bottom ruler.   This is the answer to the subtraction problem.

Example:

1/2 - 3/16  = 5/16

Now, use the slide rule to verify your answers to the following problem:

1/16 + 1/14
1/4 - 1/16
1/2   + 3/8
9/16 - 1/4
5/8 + 7/16
7/16 - 5/8 
9/16 + 1/4
1/2 - 3/8