Order of Operations
Engage
whole class and pairs
Key Language
Strategy
Use Option 2 strategies
Hear Math, See Math, Do
Math, Write Math, and
Talk Math, in the Teacher’s
Edition, Differentiated
Instruction, Small Group
Options
Language
Objectives
Activate Prior Knowledge Initiate a discussion about buying
a number of items, such as school supplies. Ask students for
suggestions of school supplies, such as notebooks, pencils, markers,
rulers. Write suggestions on the board.
Explain
Hands-on Lesson Pose a school-supplies problem to the class.
Say: Sari bought 5 pencils at $0.50 each and 2 notebooks at $1.10
each. How much did she spend? Explain that the best way to do a
word problem is to turn each part of it into an algebraic expression.
Say: We’ll use the letter p for the cost of a pencil and the letter
n for the cost of a notebook. Sari spent 5p on pencils and 2n
on notebooks. 5p and 2n are algebraic expressions. Write the
expressions, equation, and solution on the board.
●
Share and request
information.
● Follow oral and written
directions.
5p + 2n = Total Spent
5 × $0.50 = $2.50; 2 × $1.10 = $2.20
$2.50 + $2.20 = $4.70
●
Discuss when things are done in a certain order. For example,
students wake up, get out of bed, and then brush their teeth. Explain
the order of operations used in mathematics: do the operations in
parentheses first; multiply and divide from left to right; then add and
subtract. Model how to evaluate (7 × 6) + (5 × 4) using the order
of operations to solve. (62)
●
Distribute Learning Resource 24 and have pairs of fluent and
nonfluent students solve using order of operations. (56)
Math Objectives
●
Evaluate expressions.
● Use the proper order of
operations.
Math Vocabulary
algebraic expression,
evaluate, order of
operations
Lesson Vocabulary
baseball, box, calculator,
football, parentheses
Evaluate
Assessment Check students’ mastery of division as they complete
the lesson. See Assessment Checklist on page 101.
Materials
• crayons or markers
• Learning Resource 24
Beginning
Oral: Ask students to
point to the expression.
Writing: Ask them to
write the symbols used
in an expression.
94
Lesson 24
Intermediate
Oral: Ask students to
read the expression
for the school-supplies
problem aloud.
Writing: Have students
write the expression.
Advanced
Oral: Ask students to
tell you the first order of
operation.
Writing: Have students
write an expression
using parentheses.
24
Name
Order of Operations
© Macmillan/McGraw-Hill
Read the word problem below. Work with a partner to solve it.
Mr. Johnson bought some new sports equipment for the
school. He bought 7 boxes of baseballs and 4 boxes of
footballs. Every box of baseballs holds 6. Two of the
boxes of footballs hold 5 footballs and two other boxes
hold 2. How many balls did Mr. Johnson buy in all?
Look at the expression below to help you solve the
problem. Fill in your answer in the blank.
(7 6) (2 5) (2 2) boxes of
baseballs
boxes of
footballs
baseballs
per box
boxes of
footballs
footballs
per box
footballs
per box
Order of Operations
95