To find the square root of a number means we need to find what number multiplies itself to get our current product.
Let's try our basic first 5 numbers to try and see if any of them will get 16.
1 x 1 = 1.
2 x 2 = 4.
3 x 3 = 9.
4 x 4 = 16.
5 x 5 = 25.
4 x 4 is 16.
The square root is the opposite of what 16 is. The square root is actually 4, since it's number that multiplies by itself to get 16.
The square root is 4.
I hope this helps!