Question

What is the product of 21% and some number?

Answer 1

`.21x`, where `x` is some number.

Explanation:

The first step is figuring out what 21% is as a number. Well, 21% means 21 parts out of a 100 - which can be expressed as the fraction `21/100`. We could leave it like this, but decimals are easier on the eyes than fractions. To convert `21/100` to a decimal, all we do is divide, getting `.21`.

Next, we interpret "the product of 21% and some number". What is some number? The answer is in the question! Some number is any number - a decimal, fraction, number, square root, etc, etc. To represent "some number" in math terms, we use a letter called a variable. This variable just stands for some number - it can be anything you want it to be. Usually, variables are something like `n`, `x`, and `y`. We'll use `x` because that's the most common one.

Now, what does "product" mean? Multiplication! It's that easy. So the product of 21% (`.21`) and some number (`x`) is `.21` multiplied by `x`, or `.21x`.