Writing and Evaluating Expressions - Multiplication and Addition
Videos to help Grade 6 students
learn how to develop expressions involving multiplication and division from real-world problems and evaluate these expressions for given values.
New York State Common Core Math Module 4, Grade 6, Lesson 21
Plans and Worksheets for Grade 6
Plans and Worksheets for all Grades
Lessons for Grade 6
Common Core For Grade 6
Lesson 21 Student Outcomes
• Students develop expressions involving multiplication and addition from real-world problems.
• Students evaluate these expressions for given values.
Lesson 21 Exercise 1
The Italian Villa Restaurant has square tables that the servers can push together to accommodate the customers. Only
one chair fits along the side of the square table. Make a model of each situation to determine how many seats will fit
around various rectangular tables.
Are there any other ways to think about solutions to this problem?
It is impractical to make a model of pushing 50 tables together to make a long rectangle. If we did have a rectangle that
long, how many chairs would fit on the long sides of the table?
How many chairs fit on the ends of the long table?
How many chairs fit in all? Record it.
Work with your group to determine how many chairs would fit around a very long rectangular table if square tables
were pushed together.
If we let represent the number of square tables that make one long rectangular table, what is the expression for the
number of chairs that will fit around it?
Lesson 21 Example 2
Determine the cost for various numbers of pizzas, and also determine the expression
that describes the cost of having pizzas delivered.
a. Pizza Queen has a special offer on lunch pizzas: $4.00 each. They charge $2.00 to deliver, regardless of how
many pizzas are ordered. Determine the cost for various numbers of pizzas, and also determine the
expression that describes the cost of having pizzas delivered.
What mathematical operations did you need to perform to find the total cost?
Suppose our principal wanted to buy a pizza for everyone in our class? Determine how much this would cost.
b. If the booster club had $400 to spend on pizza, what is the greatest number of pizzas they could order?
c. If the pizza price was raised to $5.00 and the delivery price was raised to $3.00, create a table that shows
the total cost (pizza plus delivery) of 1, 2, 3, 4, and 5 pizzas. Include the expression that describes the new
cost of ordering pizzas.
Lesson 21 Exit Ticket
1. Krystal Klear Cell Phone Company charges $5.00 per month for service. The company also charges $0.10 for each
text message sent.
a. Complete the table below to calculate the monthly charges for various numbers of text messages sent.
b. If Suzannah's budget limit is $10 per month, how many text messages can she send in one month?
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