The pun is there in the title for those who see it. Integers form a subset of the real number system that can cause tremendous grief for Algebra teachers and students alike. Integer War is a game that many math teachers use to develop fluency with the addition and subtraction of integers, but the challenges can continue beyond these games of practice.
One of the first challenges is an understanding of positive verses negative, and the use of two-colored tiles or counters is helpful for tackling this. Red and black are great options as these colors often denote being in a negative or positive zone financially. However, by the time our students reach Algebra I, we often don’t feel like we can justify the time to go back and build visual models. When I’m working in a general education setting, I often defer to a simple team model when we are adding integers. Team Positive and Team Negative are my go-to descriptors. If the values are on the same team, the team grows, and the team sign stays the same. If the values are on opposite teams, the teams face off and cancel each other out. The team with an excess of players wins by that excess amount. It’s not as complicated when I’m in the moment. Which team wins? By how much? That tells us sign and value.
While this may seem silly, it is pretty effective for directing student thought as to what sign the sum will have and what the numeral will be.
Examples:
-3 + -6 Both values are on team negative. Team negative has 3 members and 6 more members. The net value is -9.
-5 + 12 The values are on opposite teams. Team positive wins by 7. The net value is 7.
4 + -9 The values are on opposite teams. Team negative wins by 5. The net value is -5.
If both values are on team positive, students typically don’t struggle. If the problem is set up as subtraction, I often rephrase it as adding the opposite. This way, we are looking at the addition model and are able to keep this team mentality on hand for quick reference. I don’t solve the problem for the student but rather provide the direction to help the student figure out the answer.
If you are looking for models to help support your student or students, check out my bundle, “Visual Supports for Operations with Integers“, at Teachers Pay Teachers.