Subtraction Within 20 – The Cost of Working Memory
Part of our role as educators is to continually reflect on the teaching methods and evolve them as we adjust to students’ learning. One such adjustment came about from teaching our first graders addition and subtraction for numbers within 20. Specifically, the problem of subtraction with regrouping was a major hurdle the kids had to get through. Let us look at some examples from the textbooks and workbooks, and why we decide to tweak the method for our classes.