Working with Numbers on the Graphing Calculator

Things to keep in mind when using your graphing calculator to solve number problems:

1.	Yikes! There is NO fraction key!!
	Don't panic! Just remember that the fraction bar means "divide".
	Enter	as " 3 5 ". The calculator will display .6

Mixed numbers may be entered directly.

Enter a mixed number as it is read --- " three AND (+) one half "

Enter 3 + 1 / 2

If you need to convert your decimal answer to a fraction, choose the MATH key and #1 Frac. Remember that not ALL decimal numbers can be converted to fractions. (Of course, the mixed number can also be entered as an improper fraction.)

In the examples on the left, the use of parentheses was not needed when adding, but WAS needed when subtracting (where without them, only the 2 would have been subtracted giving the wrong answer).

3.	Determine numerical equivalents.
	The calculator can be used to solve multiple choice style problems where numerical equivalents are needed. Find a decimal answer to the problem and then check each answer to see which answer matches your decimal.
	The expression is equivalent to (1) (2) (3) (4)
	Hint: Get in the habit of CLOSING parentheses. This habit will be most beneficial when working with longer problems.

4.	Working with scientific notation.
	In Normal Mode: Expressed in decimal notation, 4.726 x 10^-3 is (1) 0.004726 (2) 0.04726 (3) 472.6 (4) 4,726
	In Scientific Mode: The distance from Earth to the Sun is approximately 93 million miles. A scientist would write that number as (1) 9.3 x 10⁶(2) 9.3 x 10⁷ (3) 93 x 10⁷ (4) 93 x 10¹⁰
	Hint: In normal mode, if the answer cannot be displayed in 10 digits or the absolute value is less than .001, the answer will appear in scientific notation.

Be careful when comparing inequalities.

Calculators and computers do not evaluate "sandwich" expressions written in the form 3 < x < 10 as you might expect. They will only evaluate the first condition (3 < x). To evaluate the entire expression, you will need to "tell" the calculator to also use the second expression by using the word "and". Find "and" in the CATALOG or under the TEST menu → LOGIC.
(3 < x < 10 must be entered as 3 < x and x < 10)

If the relationship

is true,
then t could be
(1)

(2) 0

(3) (4) 4

This is a Boolean test. The 0 means the expression is FALSE. The 1 means the expression is TRUE.