Fractions

 

Adding and subtracting Fractions

Convert all the fractions so that they have the same bottom number using the method above.  Then add or subtract the adjusted TOP numbers only.  If necessary, cancel your answer.

 

Multiplying Fractions

Cancel any pairs of top and bottom numbers:              etc.  Then, do top x top and bottom x bottom.  If necessary, cancel your answer.

 

Dividing Fractions

Change , turn second fraction upside down, then proceed as with multiplication.

 

Equivalent Fractions

Work out what number is needed to multiply or divide BOTH the top and bottom numbers of the fraction

 

Simplifying Fractions

Keep dividing the top and bottom numbers until you can go no further

 

Comparing sizes of Fractions

Convert all the fractions so that they have the same bottom number.  Stat with the largest of the bottom numbers and work through its multiples until you reach a value that all the other bottom numbers will go into.  Adjust the top numbers by multiplying.  Arrange original fractions in order of size.

 

Fractions of…

 

eg.        of 27

 

·         Write the sum as:-

 

 

so  of 27  

 

·         then cancel:-

  9        

 

  1

 

 

 

·         and multiply:-

 

 

 

                                         5

eg.                 step 1

                             1

 

                                       step 2

                           step 3

 

                        OR

·         Divide by bottom number

·         Times by top number

 

eg.        of 27

 

                      divide by bottom

                       times by top

 

eg.        of £25

 

                  divide by bottom

                  times by top

 

Making Fractions

 

Always put:  and then cancel

                                                       

eg.  4 out of 10 as a fraction:

 

        2

 

              5       

                 

 etc