Multiplying Fractions

When multiplying fractions, we just multiply the numerators together and then the denominators together.  Let's look at an example:

1  *   1  =   1
3       4       12

Here is another example:

2   *   5   =   10  or 5
3        6        18      9

What if you are multiplying a fraction and a whole number?

12 *   1
          4

Every whole number has a denominator of 1, so....

12 *   1   =   12
 1       4         4

Since the fraction bar means divide, we have 12/4 which is 3.  When multiplying fractions, the product will never be larger than the sum.

We can use a brownie pan method to show the same thing.  Here is a blank, square brownie pan.

Let's say that I am selling brownies.  I have only 2/3 of the pan left.  The red section is gone.

Let's say I have a customer who wants to buy 1/4 of what I have left, or 1/4 of 2/3.  I would have to cut my 2/3 into 4th's.  It would look like this.

So now I need to color in 1/4 of what I have here.  The green shows what I would sell.

This represents 2/12 of the whole pan, or 1/6.  Mathematically:

1    *    2   =    2

4          3         12