Strip diagram subtraction generator#

How many cows were there?īefore my work with CGI and the tape diagramming it would take me a bit to figure out exactly what is going on. Secondly, the tape diagram makes complicated-sounding word problems much more manageable…įor example, there were 5 more sheep than cows on a farm. The problem may be an “Add to” problem type, but they could use subtraction to solve it if one of the addends is unknown. There is no dictate in terms of how they can find the numerical answer. If one of the smaller boxes is unknown students have a choice of adding OR subtracting. If the top box is unknown, students will need to add the two smaller boxes.

I love using Cuisenaire rods to model this using numbers within 10 – even for our upper elementary students since our goal initially is not about the computational skills to get the numerical answer, but the underlying structure of the situation. įirst, the tape diagram provides us a visual model to teach the relationship between addition and subtraction since the values of both boxes (and eventually more when there are more addends introduced) must equal the value of the large box. I find it an incredibly powerful model that allows us to teach many mathematical concepts. There is a large rectangle on top and beneath it are two smaller boxes whose size equals the large rectangle and hence the values of the two smaller boxes must equal the value in the top box. Awesome resource to create differentiated Guided Math workstations). You can select the problem type, the unknown, and the number range. (If you haven’t checked out this part of his site, I would encourage you to do so.

Strip diagram subtraction generator#

We have followed the rectangular tape diagram as found on Greg Tang’s math website within his word problem generator program. Our initiative exposes all of our students to the variety of addition/subtraction word problem types (then we’ll go on to mult/div) as based on the research in the book Cognitively Guided Instruction (and described in the CCSS) and have used the tape diagram as the way to model these situations. Read my previous post on the various problem types here: Word problems with addition and subtraction are easy, right? You may think that it seems strange to work on add/sub in the upper grades, but I assure you it is quite a complicated endeavor. This year, our school has chosen to work on addition and subtraction word problem types in our grades 3-5.