To: Teacher2Teacher Public Discussion
Different children conceptualize subtraction in different ways. For us, it is a tool for comparison and taking away. For children it is a very difficult concept. "Doing" subtraction (with markers, workjobs, place value materials) by taking away is good. However, when confronted with a problem such as 13 - 8 and an 'answer' is expected, some children and adults will count back, some will count on, some will make tens, and others will visualize another completely different way to solve it. May I suggest that you don't try to change those who count back as long as they are getting the correct answer. That's the way they SEE it in their MINDS' EYE. I remember a child who would look up at the ceiling when given a subtraction problem and after a second or two wouold tell the correct answer. He was using his tongue on the back of his teeth as a numberline! You may want to try using Workjobs as described in the book with that name by Mary Baratta Lorton. Good Luck!
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