Good knowledge of multiplying fractions! 

Before you start this lesson about multiplying fractions, I recommend that you become familiar with the multiplication table.
Half a pizza or 1/2

Multiplying fractions is very easy. However, I would like to introduce the topic with an interesting example about pizza.

Suppose that you bought a medium pizza and the pizza has 8 slices.

If someone eats half of your pizza, or 4 slices, you are left with
4 / 8
From the illustration above, you can also see that the leftover is the same as  
1 / 2

If you decide that you are only going to eat 1 slice out of the 4 slices remaining, you are eating  
1 / 4
  of the leftover.

Remember that the leftover is  
1 / 2
You can also argue that you only ate 1 slice out of 8 slices or  
1 / 8

One-eighth


Thus, we can see that eating 1/4 of 1/2 is the same as eating 1/8.

Another way to get  
1 / 8
 is to perform the following multiplication:

1 / 4
×
1 / 2
=
1 / 8

We get this answer by multiplying the numbers on top (numerators): 1 × 1 = 1

and by multiplying the numbers at the bottom (denominators): 4 × 2 = 8

This is an interesting result, but all you need to remember is the following:

When you multiply fractions, multiply the numerators together

Then multiply the denominators together.

Notice also that the word 'of' means multiplication.

More examples

3 / 5
×
4 / 7
=
12 / 35

Sometimes, it is a good idea to simplify the fractions before multiplying.

Take a look at the following example:

10 / 20
×
3 / 15


10 / 20
 
can be simplified as  
1 / 2


Divide the numerator and the denominator by 10


3 / 15
 
can be simplified as  
1 / 5


Divide the numerator and the denominator by 3

This way, it is easier to do the multiplication to get  
1 / 10

Sometimes, it is a good idea to simplify the fractions before multiplying.

Take a look at the following example:

10 / 20
×
3 / 15

10 / 20
 
can be simplified as  
1 / 2


After we divide the numerator and the denominator by 10



3 / 15
 
can be simplified as  
1 / 5


After we divide the numerator and the denominator by 3



This way, it is easier to do the multiplication to get  
1 / 10

Multiplying fractions quiz. Check to see if you can now multiply fractions.

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