In this video lesson, students investigate different ways to represent addition of signed numbers on a number line. They review what they know about negative numbers including placing them on the number line, comparing and ordering them, and interpreting them in the contexts of temperature and elevation.

Using the context of temperature helps students make sense of the addition equations. Students see that an increase in temperature can be represented as adding a positive value and a decrease in temperature can be represented as adding a negative value. When students use quantitative contexts like temperature to aid in abstract reasoning about numeric expressions with signed numbers, they engage in MP2.

Grade 7, Episode 8: Unit 5, Lessons 1 & 2 | Illustrative Math