This is a 7th Grade Math Lesson on Adding & Subtracting Positive & Negative Integers. It is designed to be a 45-50 minute face-to-face lesson, however, some materials could be adapted for an online modality. Includes materials, and interactive activities for students to participate in. 

This animated “Math Shorts” video explains the term additive inverse and provides several examples that demonstrate the concept. In the accompanying classroom activity, students create equations and solve problems that involve adding groups of negative and positive integers that sum to zero. To get the most out of this activity, students should be familiar with plotting positive and negative integers on a number line.

This article talks about the origins of our number system and the important roles zero plays in it. The author informs the reader that the early number systems of the Egyptians, the Babylonians, the Romans and Greeks were developed for counting but not for calculations. Not until we had a base ten number system with place value and a symbol for zero did our number system become useful.