Square (algebra) facts for kids

Fresnel's zone plates have rings with equally spaced squared distances to the center

In mathematics, a square of a number is what you get when you multiply that number by itself. For example, if you want to find the square of 6, you multiply 6 by 6, which equals 36.

We can also write this using a small number 2 above the number, like this: 6² = 36. This little 2 means "squared" or "to the power of 2".

The idea of a square is also used when we talk about area. For instance, a square meter is the area of a shape that is one meter long and one meter wide. It's like the space a square with sides of one meter would cover.

What is Squaring a Number?

Squaring a number means you multiply it by itself. It's a special kind of multiplication.

How to Square Numbers

To square any number, you just take that number and multiply it by itself.

• Example 1: To find the square of 5:

* 5 × 5 = 25 * So, 5² = 25

• Example 2: To find the square of 10:

* 10 × 10 = 100 * So, 10² = 100

• Example 3: To find the square of 1.5:

* 1.5 × 1.5 = 2.25 * So, 1.5² = 2.25

Why is it Called a 'Square'?

The name "square" comes from geometry. Imagine a square shape. If each side of that square is 3 units long, its area is found by multiplying the side length by itself: 3 units × 3 units = 9 square units.

So, when we say "the square of 3 is 9," it's like saying "the area of a square with sides of 3 is 9." This connection helps us understand why we use the word "square" in math.

Perfect Squares

A perfect square is a number that you get by squaring a whole number. For example, 1, 4, 9, 16, and 25 are perfect squares.

• 1 is 1² (1 × 1)
• 4 is 2² (2 × 2)
• 9 is 3² (3 × 3)
• 16 is 4² (4 × 4)
• 25 is 5² (5 × 5)

Perfect squares are important in many areas of mathematics.

Related pages

• Square number

See also

In Spanish: Cuadrado perfecto para niños