This is an activator and lesson worksheet to introduce the topic of subtraction with rational numbers. The activator allows students to use visual representations to complete 3 addition problems with rational numbers (something they should be familiar with at this point). Then the lesson has the teacher demo 3 problems using subtraction. Students then make their observations between the activator and subtraction examples to realize the visual representation are the same for both.
The standard addressed is 7.NS.1.c "Introduction to Subtraction of Rational Numbers (7.NS.1.c)" (Common Core, 2014). Students use repeated reasoning to make the connection between subtraction and addition (Standard for Math Practice #8).