## How Well Do You Understand Real Numbers?

Here is a real numbers test and key.  Before you take the test let’s do a quick review of the basics of real numbers.

Key concepts to keep in mind about real numbers:

* a real numbers is any number that is found on the real number line- these include, natural numbers, whole numbers, integers, rational and irrational numbers; these numbers express “real life” situations – one example would be temperature can be a positive or negative number
* natural number- these are the most basic numbers we count with 1, 2, 3, 4, etc
* whole numbers- these are the natural numbers plus 0, 0, 1, 2, 3, 4, etc.
* integers- these are all the whole numbers and the negative of all the whole numbers; -3, -2, -1, 0, 1, 2, 3, etc.
* rational numbers- these are any numbers we can write as a fraction using integers
* irrational numbers- these are numbers we cannot write as a fraction examples would be pi and  √7
* the rules for multiplying and dividing real numbers are the same; negative x negative = positive and negative x positive = negative
* the rules for adding and subtracting real numbers are the same; we always change subtraction problems into addition problems by using the “plus negative” step; adding real numbers that have the same sign= add and keep the same sign; adding real numbers with different signs = subtract and keep the sign of the number with the largest absolute value
* the distributive property is another way to perform multiplication
* like terms can be combined