Wednesday, March 6, 2013

The Value of Estimation

I have never been good at estimating.  Never once did I even try to estimate my answers in college.  I was always a formula guy.  I would substitute the variable and make the formula/equation do what it do (as Ray Charles would say).  Luckily for me I was introduced to twitter by my district's tech coach  and on there I found  .  I read his posts and came across his idea of daily estimations(estimation180).  I wasn't convinced of the benefit of having students do this.  Not until I talked with a coworker, , did I see the power this could have.  Pat relayed how his students were starting to estimate out their math answers before starting their calculations in class.  He said that he simply would put the image up at the start and have the kids make their estimates and be done in the first couple minutes of class.

This inspired me!  I am all about implementing a low input <=> HIGH OUTPUT product into my class.  So, I started.  Each day I would start class with an image on the projector with the daily estimation problem.  Kids would come in and know they had a minute to write down their guess before I showed them the result. (BTW: I am Type A, so they have a document to fill in!)
I also wanted them to analyze their guess.  After each answer I had them write a +/- number to show how above/below their estimate was to the actual answer.  Finally, after 20 days of estimating, I would have them average their +/- numbers to get their average 'error'.  My highest student error was in the 1,000's and my lowest was 0.4.

Now, I have not yet had kids translate this estimation into their regular daily lessons, but I believe it will happen.  Like anything it is a process.  Slow and steady wins the race!

Finally, I saw a post on Twitter about a calculator that won't give you the actual answer until you type in your best estimate.  This nearly floored me.  Talk about having the best of both worlds: using a calculator to speed up your work, but also THINKING while using a calculator!