HANDY MATH FACTS TO KNOW

It's expected that people know their basic addition and multiplication facts but if you tend to be forgetful, some basic drill might be lifesaving.

It's helpful to be familiar with basic squares, cubes, some square roots and the powers of 2. The basic squares are the squares of the counting numbers. For example, when we get to the Pythagorean Theorem in geometry it will be convenient to know that =169. When we want the volume of a cube that has an edge of 4 inches, it will be handy to know that = 64. When you encounter probability problems it might be convenient to know the powers of 2. For example, the odds of getting 5 heads in a row is = . Knowing some square roots is helpful in geometry. For example, the diagonal of a square that is 3 inches on a side is , which is about 3 x 1.4.

Of course, with the availability of calculators, knowing basic facts might seem less important than it used to be. However, even plugging numbers into the calculator takes a little time and every moment shaved off computation gives you more time for other problems.

The table lists some facts that might be useful to memorize.

Perfect Squares	Perfect Cubes	Powers of 2
1 = 1	1 =1	= 2
2= 4	2 = 8	= 4
3 = 9	3 = 27	2 = 8
4 = 16	4 = 64	= 16
5 = 25	5 = 125	= 32
6 = 36		= 64
7 = 49	Square Roots	= 128
8= 64		= 256
9 = 81	= 1	= 512
10 = 100	1.4	= 1024
11 = 121	1.7	1000 =
12 = 144	= 2
13 = 169	2.2
14 = 196
15 = 225