6th grade Math6.EE.2c

I CAN EVALUATE ALGEBRAIC

EXPRESSIONS

Vocabulary

Variable: a letter that is used to represent a number. Variables are always lowercase letters.

Algebraic Expression: a mathematical phrase that has at least one variable; it can contain numbers and operation symbols. It does NOT contain an = sign.

NotesTo evaluate an algebraic expression:

•You replace each variable in the expression with a number or numerical expression

•Perform all possible mathematical operations following the order of operations.

PEMDASParenthesis

Exponents

Multiplication

Division

Addition

Subtraction

Notes

• Anytime you have a number beside of a variable (example: 3x) or two variables side-by-side (example: xy) ----- this represents multiplication.

• Anytime you have a variable by itself, there is an understood “invisible” 1 in front of the variable, but you NEVER write the 1.

Ex.: 1x is written as just x.

5

Evaluate each expression.1. 7b, for b = 5

2. 5 – c, for c = 3

3. 5x + , for x = 2

4. 4c – 7 + 2d, for c = 2 and d = 5

More Examples5. 6 ÷ a + 8, for a = 2

6. ÷ 8, for x = 8

7. 3n + 2, for n = 7

The formula P = 2l + 2w gives the perimeter P of a rectangular room with the length l and width w. A rectangular living room is 26 feet long and 21 feet wide. What is the perimeter?

Task Cards•Write down the problem once you substitute in for the variable.

•Then solve.