Opener: Please also put your Nspire (with Nspire faceplate on) on my
desk. If you need to put your name on it, there are Sharpie
markers on my desk.
Please put up your
defined variable and 1. Match each expression to a set of steps.
expression to one of I. ‐3(x ‐ 4) II. ‐3x ‐ 4 III. 4(x ‐ 3)
A. Choose any number. Subtract 3. Multiply by 4.
B. Choose any number. Subtract 4. Multiply by ‐3.
you feel good about C. Choose any number. Multiply by ‐3. Subtract 4.
AFTER you finish the
opener. 2. Write an expression for the area of a rectangle with
length 10 and width w.
3. Simplify: ‐2 + 4[3 ‐2(5+5)] ‐ 10
Section 2.3: Evaluating Expressions
Last class period, we learned how to write expressions to
To evaluate an expression, we replace the variable with a
Example 1: If you drop an object, its speed after t seconds is
given by the expression 32t. How fast is the object travelling
at the times listed in the table below?
Time, t, in secs Speed, 32t, in ft/sec
Example 2: Write an expression for the following number
Choose a number. Add 6. Multiply by 3. Subtract 10.
Once you have the expression written, what will Spiro's
ending number be if he chooses ‐2 as his starting number?
More Evaluating Sometimes you will be asked to evaluate an expression
Expressions: that doesn't come from a real situation.
Example 3: Evaluate the expression 2 ‐ 3(x + 5) for the
following values. (Show work for all problems.)
A. x = 1 B. x = ‐3
C. x = 9 d. x = ‐7
Nspire Activity: You need your calculator with the Nspire faceplate
attached to complete the activity today. This activity will
be worth 10 daily work points. You will turn it in before
you leave today.
You are working with your partner, but use the other
two people in your group if you and your partner get
stuck and I am helping someone else.
When you finish, raise your hand for your next task.