the FOIL method for mental multiplication of binomials

I'm Manny the method magician.

Now back in ancient mathematical history, like the 1960's and 70's, people used to use a little acronym to help them multiply two binomials together mentally.

It was called the FOIL method. The letters reminded you what order to multiply the terms so that you did not leave anything out.

Let's consider the above example again.

F reminds you to multiply the first terms in each binomial (the two x's in our example).
O tells you to multiply the outside terms in each binomial (the first x and the 5).
I reminds us to multiply the inside terms (the 3 and the second x).
L tells us to multiply the last terms (the 3 and the 5).

Often the O and the I will be like terms and you can add them together.
So the mental trick is:

Write down the first product
Get the outside product and inside products, and add them together if possible. Then write the result beside the first product.
Finally write down the last product.

Let's try a few. Click the answer link to see if you are correct.

Click HERE for the answers.

We hope these are what you got!