Unit Rate Grocery Shopping

Learning Resource Type

Learning Activity

Subject Area

Mathematics

Grade(s)

Overview

Students will practice the concept of unit rate by comparing the prices of various items in grocery store advertisements.

This activity results from the ALEX Resource Development Summit.

Phase

After/Explain/Elaborate

Mathematics (2019) Grade(s): 6

MA19.6.2
Use unit rates to represent and describe ratio relationships.

Vocabulary

Unit rate
Ratio
Rate language
Per
Quantity
Measures
Attributes

Knowledge

Students know:

Characteristics of multiplicative comparison situations.
Rate and ratio language.
Techniques for determining unit rates.
To use reasoning to find unit rates instead of a rule or using algorithms such as cross-products.

Skills

Students are able to:

Explain relationships between ratios and the related unit rates.
Use unit rates to name the amount of either quantity in terms of the other quantity flexibly.
Represent contextual relationships as ratios.

Understanding

Students understand that:

A unit rate is a ratio (a:b) of two measurements in which b is one.
A unit rate expresses a ratio as part-to-one or one unit of another quantity.

Learning Objectives

Students will be able to identify the unit rate of items and discuss the concept of a unit rate.

Activity Details

Begin by asking students where they go grocery shopping. Ask students if they know why their parents have chosen the store they like. Explain that different stores have different prices for the same items.

The students will find five different items in three different stores using online ads. They should use the size of the item and the price advertised to find the unit rate from each store. The students will record the size and price for each item on the recording sheet and then calculate the unit price. They should circle the store that has the lowest price for each item.

Model the first example by finding the item in different ads (produce and beverage items work well). Model recording the price and quantity of each, and then review how to find the unit rate.

In closing, ask questions such as:

Which store had the lowest prices?
Did any of the price differences surprise you?
Do you think stores expect shoppers to calculate the unit rate before shopping?
Why might someone buy an item with a higher unit rate?

Assessment Strategies

Check for understanding of the concept of the unit rate as the students are working. Ask students to explain how they chose which store to circle for each item; watch to be sure students aren't choosing the lowest overall price rather than the lowest unit price.

Variation Tips

You can allow students to work in pairs or in small groups depending on ability.

Enrichment: Challenge students to create their ideal shopping list and find the unit price of each item. How many people would the list feed? How much would it cost to feed a family of four?

Background / Preparation

Make enough copies of the recording sheet for each student (or pair of students). You may want to post the link to the Sunday Saver website so students don't have to type in the URL.

http://www.sundaysaver.com

Approved Date

2019-05-05

Owner (Author)

seasley

Design by Adaptive Theme