Which Price Is Right?

Students in Middle School math teacher Karen Seder’s class recently learned about ratios by working on an authentic math problem. They calculated and then compared the unit prices of commonly purchased groceries like chips, cereal, and soup to figure out which was the best deal. Since different packages have different volumes, a bag of chips that cost $2.99 wasn’t necessarily a better deal than a different bag that cost $4.99.

Working with a partner, the students first guessed which of the three items in each category was the best deal and then used their math skills and calculators to work out the relationship between cost and volume to determine the actual unit rate. They moved from station to station until they had completed three challenges.

Seder said, “I love this activity because it is so hands on. The students are more engaged because they have the actual items to hold as they do the problem. They have to learn to read a grocery store receipt and determine where to find volume on the various food items. It is a super way to make unit rate real.” 

Afterwards, the class donated the food items to Doorstep Donations. Keep an eye out for these savvy shoppers the next time you're in the grocery store!