# Percentages

Of all of the topics in pre-algebra mathematics, taking percentages is probably the easiest topic that is misunderstood by the largest number of people. I say percentages are easy because they are just a sneaky way of saying multiplication.

If you want to take a percentage, you move the decimal point of the percentage twice to the left and multiply.

So if you want to take 25% of 8, you’d do .25 * 8 and figure out pretty quickly that the answer is 2.

That’s all there is to it. To help you get the hang of it, here are some examples.

#### Example 1: Find 30% of 12.

We move the decimal point of 30 two spaces to the left to get .30 and multiply that times 12 to get 3.6. So 30% of 12 is 3.6.

#### Example 2: At a sale, what is 20% off of \$15?

First we have to find what 20% of \$15 is. So we move the decimal point of 20% to the left twice to get .20, and multiply that by \$15 to get \$3.

Now we subtract \$3 from \$15 to get \$12.

#### Example 3: What is 8% sales tax on a purchase of \$227?

By now I’m sure you have the hang of it. This is just .08 times \$227, which is \$18.16.

Let’s do something harder.

#### Example 4: What’s 35% of 27% of 87% of 1600?

I’m pretty sure someone at some point will read this problem and have a panic attack. But it’s not difficult unless you psyche yourself out! Start at 87% of 1600:

.87 * 1600 = 1392

Now take 27% of that:

.27 * 1392 = 375.84

And finally, take 35% of that:

.35 * 375.84 = 131.544

So 35% of 27% of 87% of 1600 is 131.544.