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Accepting that learning of some topics will interfere with other topics is the first step to recovery.

By accepting that leaning learning of some topics will interfere with the learning of other topics and embracing this - we are able to help the students decouple correctly match the ideas and the names attached to those ideas. 

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Here are a number of problems that will interfere with each other initially

simplify sum and product

Once we start to teach how to simplify h x h x h x h students lose their confidence  in knowing that h + h + h + h = 4h  .... so as soon as you teach h x h x h x h get students to work on and compare with h + h + h + h type problems, ideally in a mixed bag over time.

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