HOW TO WORK WITH FRACTIONS

 

      numerator (top)  _
  denominator (bottom)

A fraction actually means: divide the top by the bottom.

1/2 means "1 divided by 2." 

This is why working with fractions can be confusing. We are adding, subtracting, multiplying, and dividing divisions.

 

 


 

HOW TO ADD FRACTIONS

 

to add ½ + ½  

just use 2 as the denominator of the answer because both fractions have same denominator.

So ½ + ½= 2/2 = 1

 

Add 1/2 + 1/3 

you have to convert each fraction to another fraction so that each has the same (or 'common') denominator. 

The easiest way to find a common denominator is to multiply the first denominator by the second.

In this case, 2 x 3 = 6, so we convert 1/2 and 1/3 to fractions with six in the denominator.

1/2 = 3/6  and 1/3 = 2/6

so

1/2 + 1/3 =

3/6 + 2/6 =

5/6

 


 

HOW TO SUBTRACT FRACTIONS

 

Subtract 1/2 - 1/3 

you have to convert each fraction so that each has the same (or 'common') denominator. 

The easiest way to find a common denominator is to multiply the first denominator by the second.

In this case, 2 x 3 = 6, so we convert 1/2 and 1/3 to fractions with six in the denominator.

1/2 = 3/6  and 1/3 = 2/6

so

1/2 - 1/3 =

3/6 - 2/6 =

1/6

 


 

Multiplying fractions is the easiest. 

Multiply the top by the top, and the bottom by the bottom

1/2 times 1/3 = 1/6

 


 

HOW TO DIVIDE FRACTIONS

 

'Flip-it-over' and multiply.

1. Change the ÷ sign to x and invert the second fraction.
2. Multiply the numerators.
3. Multiply the denominators.
4. Reduce the results.

1/2  ÷  1/3  = 

1/2  X  3/1  = 

3/2 =  

1½ 

 

To divide a fraction by a whole number, make the whole number 'over 1', and then 'flip-it-over'.

1. Convert the whole number to a fraction (3 becomes 3/1).
2. 'Flip-over' the new fraction (now 1/3).
3. Multiply the numerators.
4. Multiply the denominators.
5. Reduce the results.

1/2  ÷  3 =  

1/2  ÷  3/1 =   

1/2  X  1/3 =  

1/6  

To divide a whole number by a fraction, make the whole number 'over 1', and then 'flip-over'.

1. Convert the whole number to a fraction (3 becomes 3/1).
2. 'Flip-over' the other fraction.
3. Multiply the numerators.
4. Multiply the denominators.
5. Reduce the results.

1/2  ÷  3 =

1/2 ÷ 3/1 =

1/2  X  1/3 =

1/6 

 

Remember: A fraction is a division. Look at the division sign on your calculator. It is actually a fraction. So dividing fractions is dividing divisions.

Good Site: VISUAL FRACTIONS