Squares
The square of a number is the number multiplied by itself. For example, four squared, 42, is 4 × 4 = 16.
This can be shown as a diagram.
A square of side length 4 cm has an area of 4 cm × 4 cm = 16 cm2.
![4 by 4 grid Square 4 cm by 4 cm. Gridlines at 1 cm intervals](../../image/Y7_1h_1.png)
The square root of a number is the number that when multiplied by itself gives the original number.
To illustrate:
6 × 6 = 36, so six is the square root of 36. We write \(\sqrt{36}=6\).
11 × 11 = 121, so 11 is the square root of 121. We write \(\sqrt{121}=11\).
Geometrically, the square root of a number is the side length of a square whose area is that number.
![](../../spacers/spacer40.png)
![](../../spacers/spacer40.png)
![](../../spacers/spacer40.png)