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Welcome to my math blog! The purpose of this blog is to help you stay informed about our learning and experiences that have taken place during our math class. I have also included links your child (and you) may want to use in order to supplement math learning in 5th grade.

Wednesday, November 4, 2015

Decimal Operations: Multiplication 3 Act Math

We moved into multiplication of decimals today.  I wanted to make this intro a little more entertaining, so we did a Kahoot and a 3 Act Math activity.

To begin, I had to explain that all of the emphasis I put on lining up the decimal point when adding and subtracting decimals, goes out the window when we multiply decimals.

I explained that we have a new set of rules:

I decided to allow the classes to "play around" with this new set of rules by playing a Kahoot.  I created a survey with 4 problems.  I chose to use the survey format because there is no stress on being right and winning... helps calm the nerves!

After completing our quick activity, I had the students create a new Google Doc in their math classroom to help them solve our 3 Act Math problem.  I began by having them watch an Esurance Commercial about saving a ton of dollars.  This was the "hook."  

Once we viewed the commercial, I asked the students what they wanted to know after seeing this commercial (Act 1).  It took a little guidance, but we finally go to "How many dollars are in a ton?"  At this point, I asked them to make a prediction.

Act 2 is about gathering information.  I asked the students what we needed to know in order to answer the problem.  Students knew there were 2000 pounds in a ton. So, they wanted to know how much a dollar weighed.  We discovered that a dollar is about one gram.  Well, now we need to know how many grams are in a pound (453.594).  

Act 3 is using the information to solve the problem.  The students explained that there are $453.594 dollars in a pound so we needed to multiply that by 2000.  We chose to multiply 453.594 by 2 and then add our three zeroes.  At this point we used our new found information to place the decimal in the correct spot, add our place value commas, and voila.... the number of dollars in a ton!

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