Expressions and Equations5.ATO.1 Evaluate numerical expressions

involving grouping symbols (i.e., parentheses, brackets, braces).

5.ATO.2 Translate verbal phrases into numerical expressions and interpret numerical

expressions as verbal phrases.

What do I have to do?

By the end of this unit you will be able to:– Create an expression or equation from a word

problem

– Use variables to represent what you don’t know

– Explain why a specific expression or equation does or does not represent a word problem

– Create a word problem for a specific equation

#8-1 – Using Variables

• Take out your math textbook and math journal

• In your journal, copy these notes:– A variable is a part of the math problem that you

have to figure out the value of• A variable is represented by a letter

• A variable can CHANGE values

– An algebraic expression is the first part of an equation and does not have an equal sign• An algebraic expression must have a variable and an

operation (+, -, x, ÷)

Using Variables to Write Expressions

• Put your math journal under your textbook

• Turn to page 194 in your textbook, follow along as we take turns reading from the section “Other Examples”

• Now I will model problems 1-4 on page 194, wait for me to ask for your help

WE DO – Try this!

• Let’s work on problems 5-7, you’re going to help!

• Raise your hand, read the problem, give your answer

WE DO – Try this! ANSWERS

• #5) n = number of CDs

• #6) the variable is “y” the operation is multiplication

• #7) (8 x 3) + n

YOU DO – Practice on your own

• Write your name and date on a blank sheet of lined paper

• Complete problems #8 – 19 on page 195

• Turn in by 9:20am

• If you finish early, complete the RETEACHING SIDE of 8-1 in your workbook, do not turn in

Review and Reflect

• In your journal, try to write a word problem that might require a variable.

8-2 – Order of Operations

• Take out your math textbook and math journal

• In your journal, copy these notes:– Order of Operations

• If you are given the value of the variable, plug it in

• Do the expression(s) inside (parenthesis) first

• Then multiply and/or divide from left to right

• Finally, add and/or subtract from left to right

Order of Operations

• Put your math journal under your textbook

• Turn to page 196 in your textbook, follow along as we take turns reading from the top of the page and the section “Another Example”

• Now I will model problems 1-4 on page 196, wait for me to ask for your help

WE DO – Try this!

• Let’s work on problems 5-6, you’re going to help!

• Raise your hand, read the problem, give your answer

WE DO – Try this! ANSWERS

• #5) Juan added and divided first instead of dividing then multiplying

• #6) (3+5) x 2 – 10 = 6

YOU DO – Practice on your own

• Write your name and date on a blank sheet of lined paper

• Complete problems #13-28 (all) on page 197

• Turn in by 9:20am

• If you finish early, complete the RETEACHING SIDE of 8-2 in your workbook, do not turn in

Review and Reflect

• In your journal, write three expressions that have three or more operations and a set of parenthesis. Was that hard to do?