Construct It! Introducing Integers with Floats and Anchors

As students have struggled to use the "chip model" (i.e., red and yellow chips representing positive and negative numbers) to model integer addition and subtraction and have found it confusing, the authors developed a series of activities based on adding and removing opposite objects to and from a boat to better help students in this area of mathematics. In this article, they describe a sequence of four Floats and Anchors activities that they use to introduce integer addition and subtraction. This "Construct It!" task typically takes between 50 to 75 minutes of class time and requires no prior knowledge of integers. This task sets students up to successfully use both the chip model and a vertical number line as tools for reasoning about integers.