In this segment, Travis Lemon, a math teacher from American Fork Junior High School in American Fork, Utah, guides his students to solve a real-world problem using linear equations. Travis’s lesson targets eighth-grade Common Core math standard Expressions and Equations eight and Mathematical Practice standards four through six. Elements of related standards are also highlighted in this segment.

“Often when I teach, I use a contextual type of a task where it’s a scenario or something real-world that they can connect with.

‘So Ivan’s furnace—it’s quit working during the coldest part of the year. He’s eager to get it fixed. He decides to call some mechanics. He’s not sure about parts, so he’s going to focus on the labor expense to help him make his decision.

“Company A, they charge a $20 service fee just for coming out to his house and then a $25 per hour charge on top of that. Company B, they charge $35 per hour flat rate. Company C, they charge a $45 service fee just for coming out to the house and then $20 per hour. So here’s your task: figure out for which time intervals Ivan should choose company A, company B or company C.

“You’re welcome as always to use the tools you have. The calculators, I have graph paper out. There are some up here on the chair and there’s some back in the corner as always.”