# How much is two square

## Square Numbers - How To Calculate Them?

### Square numbers

As Square numbers one denotes all numbers that have the Product of a natural number with itself are. Natural numbers are all whole numbers greater than \$ 0 \$, i.e. \$ 1,2,3, ... \$ and so on. The term comes from the fact that when we multiply two numbers, we can imagine a rectangle with the first number as the width and the second as the height. If the first and the second number are the same - let's multiply a number by itself - the result is a rectangle whose height is equal to its width. Such a rectangle is a square.

Let's look at the natural number \$ 7 \$ as an example. If we multiply this by itself, we get:

\$ 7 \ cdot 7 = 49 \$

That means \$ 49 \$ is a square number. They say, "\$ 49 \$ is the square of \$ 7 \$."

So that we don't always have to write out multiplying a number by itself, we use the Power notation. This allows us to write \$ 7 \ cdot 7 \$ as \$ 7 ^ 2 \$. You then say: “\$ 7 \$ to square is \$ 49 \$. "

If possible, memorize the squares of the numbers from \$ 1 to \$ 20:

\$ \ begin {array} {c | c || c | c} number & square number & number & square number \ \ hline 1 & 1 & 11 & 121 \ 2 & 4 & 12 & 144 \ 3 & 9 & 13 & 169 \ 4 & 16 & 14 & 196 \ 5 & 25 & 15 & 225 \ 6 & 36 & 16 & 256 \ 7 & 49 & 17 & 289 \ 8 & 64 & 18 & 324 \ 9 & 81 & 19 & 361 \ 10 & 100 & 20 & 400 \ end {array} \$

For example, recognizing square numbers can help you identify the binomial formulas or when calculating faster root help.