Explaining Conventions 1: dividing fractions

I think I’ll include a little sub-section for people like me (i.e. inexperienced teachers) for topics and conventions that aren’t easily explained, or where there is a ‘rule’ that can be applied without being understood. Most of these posts will be pilfered from others.

Today’s is ‘why do we turn the second fraction upside down?’

A good little slideshow (in terms of content) is can be found here. For those reluctant to navigate away (ha!), here is a summary:

I think this will appeal to some of my classes – but will have to formulate a neat explanation of reciprocal without sending the lesson off in the wrong direction…

1 Comment

Filed under Education, Explaining conventions

One response to “Explaining Conventions 1: dividing fractions

  1. sdmathtutoring

    It might be good to put in an extra step before 4/6 divided by 12/12. if you keep the multiplication as 1/2 * 4/3 divided by 12/12 then simplify, it shows it more directly.

    this of course depends on your students. I find that just mentioning fractions starts panic attacks, so I try to be as explicit as possible.

    This is great for an algebra class for students who are comfortable manipulating fractions but don’t understand the rules.

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