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Sunday, May 20, 2012

Fraction Estimator - Visualizing Conversion

When I was in the math classroom I was continually aware that students' problem solving skills were hindered by their inability to visualize concepts.  Proportions and multiple representations of values were simply steps the students tried to remember for a quiz rather than a concept that would come in handy (and often was absolutely necessary) for solving a variety of real world problems.

Approaching problem solving with steps instead of a conceptual understanding is like trying to get from my home in Michigan to my in-laws' house in Florida by memorizing every turn.  Even if I can remember the list, let's hope there's no unexpected construction along the way.  A conceptual understanding would be like having a map.  It's the big picture and it comes in handy even when the unexpected comes along.

When our district purchased Promethean Boards and I started experimenting with ActivInspire I realized I finally had a tool that would let me show students some of the ways I visualized concepts.  One such tool I created is a fraction estimator.

With all the multiplying and dividing going on in a typical conversion problem, most students never stop to consider we are always talking about the same value.  One-fourth is exactly the same amount as 0.25 or 25%.  This fraction estimator provides a good visual for explaining this.  When I used it with students they picked up on the concept quickly.  While it does not provide exact answers in conversions, it gives students the conceptual tool that will help them make connections when solving problems that require such understanding.

The flipchart version for ActivInspire is here.  I also have a single slide in Google Docs that can be used if you don't want to download ActivInspire*.

This video shows how to use it:

*The Google Docs version is limited in a few ways.
  • You can't write the numbers on the slide without using other software.
  • You won't be able to fill the sections of the bars with another color.
  • It's not as easy to line up the bar with the scale because the bar is not displayed as you move it.
  • If it's too small, go to the View menu and pick Full Screen.

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