Sunday, October 14, 2012

Singapore Math Method for Compensation Subtraction

After years of doing intervention work with subtraction across a zero, I was so excited when I learned about compensation subtraction.  It's also called constant difference.  It helped so many kids and it wasn't just a trick.  They understood why they were doing it!
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When I taught larger numbers, I generally reverted to the traditional method, or used many steps.  After spending a really fun week in Cleveland, MS, Lon Hayes sent me an email describing this method of compensation subtraction with larger numbers.  Thanks so much Lon!!
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Try this with your class and let me know how it goes!

Wednesday, October 3, 2012

Singapore Math--Extending a Problem

This was a comment on another post...I just wish I had the original problem!

Today I posted some of the part/whole problems around the classroom for student pairs to go around and make models/solve. I had one kid that needed more of a challenge, so I asked him to write more problems... Here are his two problems: Joe bought 26 chairs. They each cost $7.25. How much money did he have to pay? 


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 Logan made 64 chairs. He needs 6 wood planks to make 2 chairs. How many planks does he need to make 64 chairs?


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