Addition Subtraction Kit

Designed to teach the student addition and subtraction facts. By internalizing the basic concepts of regrouping and reshaping the student will learn the addition and subtraction facts with ease. Contains two each of the unit bars from l-9 and cards with addition and subtraction facts – control of error on the reverse.

The following video shows how very young children are able to understand the concept of addition and subtraction by using this kit.


  1. Hello!

    I am trying to understand how this product is used. I think i get the jist of it, but i wondered about the 8 sections containing equations. The blue is addition and the yellow subtraction, but why are there four compartments for each? I figured that static and dynamic addition would each get their own section…are there other kinds?



    1. Jessica the kit is designed to teach basic addition and subtraction facts by helping children internalize the concepts of regrouping and reshaping. You could sort the problem cards into different compartments from easy to difficult and static versus dynamic. You could also fill the compartments with just addition cards or just subtraction cards. Or you could sort the cards with specific augends, addends, minuends, and subtrahends. Really it is up to you if and how you sort the cards in the compartments. You can also turn the cards over to the answer side and make up your own problems as this kit includes addition, subtraction, and same as sign cards. There is no right or wrong way to put the cards in the compartments. Be creative and do what works for you and your child. The beauty of this kit is that it is visual, tactile, and has control of error built in.

      1. Okay, thanks! I guess i was wondering if there was a specific reason why there are four/eight compartments. Me background in montessori materials tells me that if something is there, its there for a reason. Is it just because they fit conveniently over the top of the number bars? Thanks!

      2. My opinion is that they are mostly there just to fit the cards in conveniently over the top of the number bars as there is nothing to indicate otherwise in any of the Mortensen More Than Math materials. Unfortunately Jerry is not here to ask otherwise I would enquire further with him.

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