1. Variables and Expressions
Lesson 11
Variables and Expressions

2. Review! Vocabulary Variable:
a symbol used to represent numbers or values.
Algebraic Expression:
one or more numbers and variables with one or more arithmetic operations

3. What do expressions look like?
Here are some examples 5x
3c – 7
4 + p/2
Can you give some examples?

4. Writing Expressions - Adding
Add 9 and 3  9 + 3
The sum of x and 4  x + 4
x more than -2 (switch)  -2 + x
8 plus y  8 + y
Can you think of any other words that are the same as adding??

5. Writing Expressions - Subtracting
Subtract x from y  y – x
Subtract x and y  x – y
The difference of c and 4  c – 4
5 less than t (switch)  t – 5
8 minus y  8 – y
Can you think of any other words that are the same as subtracting??

6. Writing Expressions - Multiplying
Multiply -4 and h  -4h
The product of 3x and 7  7(3x)
9t multiplied by -3z  9t(-3z)
8c times -2y  (8c)(-2y)
Can you think of any other words that are the same as multiplying??

7. Writing Expressions - Dividing
Divide 8x and 6y  8x ÷ 6y
The quotient of 9 and 3x  9 ÷ 3x
5y divided by -2  5y ÷ -2
Can you think of any other words that are the same as dividing??

8. Writing Expressions - Exponents
A number squared  y2
The cube (or third power) of a number  3x3
Can you think of any other words that are used for exponents??

9. Write the expression for the following
PRACTICE TIME!
Write the expression for the following
The sum of a x and 3 times y squared
5 decreased x to the third power
The quotient of 5 plus y and 3 decreased by x
8x + 2
3 ÷ 2y2