Multiplying Fractions

Multiply the tops, multiply the bottoms.

There are 3 simple steps to multiply fractions

1. Multiply the top numbers (the numerators).

2. Multiply the bottom numbers (the denominators).

3. Simplify the fraction if needed.

 

Example:

1 × 2
2 5

Step 1. Multiply the top numbers:

1 × 2 = 1 × 2 = 2
2 5    

Step 2. Multiply the bottom numbers:

1 × 2 = 1 × 2 = 2
2 5 2 × 5 10


Step 3. Simplify the fraction:

2 = 1
10 5

With Pizza

Here you can see it with pizza ...

... and do you see how two-tenths is simpler as one-fifth?

 

With Pen and Paper

And here is how to do it with a pen and paper (press the play button):

 

 

Another Example

1 × 9
3 16

Step 1. Multiply the top numbers:

1 × 9 = 1 × 9 = 9
3 16    

Step 2. Multiply the bottom numbers:

1 × 9 = 1 × 9 = 9
3  16 3 × 16 48


Step 3. Simplify the fraction:

9 3
48 16


(This time we simplified by dividing both top and bottom by 3)

The Rhyme

"Multiplying fractions: no big problem,
Top times top over bottom times bottom.

"And don't forget to simplify,
Before it's time to say goodbye"

Fractions and Whole Numbers

What about multiplying fractions and whole numbers?

Make the whole number a fraction, by putting it over 1.

Example: 5 is also  5
1

Then continue as before.

Example:

2 × 5
3

Make 5 into 5/1 :

2 × 5
3 1

Now just proceed as normal.

Multiply tops and bottoms:

2 × 5 = 2 × 5 = 10
3 1 3 × 1 3

The fraction is already as simple as it can be.

Answer =   10
3

Or you can just think of the whole number as being a "top" number:

Example:

3  ×  2
9

Multiply tops and bottoms:

3  ×  2  =  3 × 2  =  6
  9  9 9

Simplify:

6  =  2
9 3

 

Mixed Fractions

You can also read how to multiply mixed fractions

Worksheets