This blog post features a sliding ruler approach to modeling the addition and subtraction of integers. Rather than memorizing rules for solving problems like 9 + (–14) or -2-(-7), students can develop completely general methods that focus on conceptual understanding.
Tag Archives: subtraction
Revisiting the Hundred Chart
With a few adjustments, we can make the Hundred Chart more intuitive and more useful for students. This post explains why the improvements are needed and describes how students can build a physical model that more accurately corresponds to the number system.