1. Numbers Free powerpoints at http://www.worldofteaching.comhttp://www.worldofteaching.com

2. Perfect Square Squares of whole numbers

3. Square root One of two equal factors of a number. If a squared equals b then a is the square root of b. The square root of 144 is 12 because 12 squared is 144.

4. Radical Sign The sign used to represent a nonnegative square root.

5. Principle Square Root A nonnegative square root

6. Irrational Number Numbers that cannot be expressed as a/b.

7. Real Number Irrational numbers together with rational numbers to form the set of all numbers.

8. Natural Numbers 1, 2, 3, 4...

9. Whole Numbers 0, 1, 2, 3, 4, 5...

10. Integers The whole numbers and their opposites....-3, -2, -1, 0, 1, 2, 3...

11. Rational Numbers Any number that can be expressed in the form a/b where a and b are integers and b is not equal to 0.