We've Been Sharma-ed - Mahesh's Visit to Grade 3

It's always exciting (for me, at any rate) to have the opportunity to come together with colleagues to improve our understanding of math and math instruction.  This week we had a special guest, Mahesh Sharma, who came to WCSU for clinical rounds.  Lots of folks were able to attend various "rounds," but since I was able to attend all four rounds, I thought it might be helpful to document and share what went down... 

Monday, December 7 

After some delicious beverages and treats (and I spilled an entire cup of tea all over the lovely spread because obviously, someone needs to have caffeine before leaving home), we started with a discussion of place value...

Ever wonder why the names billion trillion, quadrillion, etc.?  Pictured at left, Mahesh explained that the word "million" comes from mille which means "one" and llion which means "group."  

I was unable to substantiate this (fact checking found that the etymology of million is that mille means "thousand" and  the addition of the suffix -ion changes the meaning to "a great thousand"). 

Fact checking aside, I liked Mahesh's explanation that the naming has to do with the number of "groups away from 1000" where a "group" is defined as having ones, tens, hundreds.  So 237,000,000,000 is "two hundred thirty-seven" and the group name is trillion because it is three groups away from one thousand.

Then we talked about the importance of learning subtraction strategies (tool building with mental math and open number line visuals) rather than moving to the standard algorithm too soon without understanding.

Then, we watched Mahesh introduce multiplication in a third grade class.  Here is a link to my notes of the lesson.

First some tool building - Counting up by one fifth from 7. 

Concept building - A student makes concrete model to represent 8+8+8

The board at the end of the lesson.

After the lesson we debriefed and had a great discussion of fractions.  I snapped some photos of Mahesh's note on fractions...

The questions to ask when teaching fractions.

By the time students are in sixth grade, they need to see fractions all ten of these ways. 

Then as a special treat, Mahesh worked with two students in interventions and was willing to let me video tape it.  See the video below.  Check out this post of number concept for more information about what he was trying to accomplish. It's all about building number concept!

What were your takeaways?

Stay tuned.  I've got three more posts up my sleeve to round out the visit...