Oct 2, 2014

Connecting Addition and Subtraction


 How do you teach addition and subtraction?  Do you teach one first and then the other?  Do you teach them at the same time?

Not sure what the right answer is.

We have been touching on both this year and working hard to build that number sense.  But we had not been explicit about the connections between addition and subtraction.  But the time has come.

Jess and I started with this:


 We introduced the "whole-part-part" with hula hoops by asking: "What do you see?"  And guess what...?  Our number talks must be working because they replied with:
 "Oh, I see two balloons and two more balloons. 2 and 2 make 4."
"I see two small hula hoops and one big hula hoop.  2 and 1 make 3."

Yep!! We love it!!

Our lesson was ready to start!  We explained the whole number and how it can be broken into parts.

(Sorry, this example is with the whole number: 5.)
We broke the number into two parts (subtraction) and showed how we can then put the numbers back together (addition).  It was SO..MUCH..FUN!  The kids were engaged and excited to help us break apart these numbers.

We helped them transfer this learning to paper.


This lesson is the foundation for our week of addition/subtraction lessons.  Here are some activities we found (click on them for their original posts) and decided to use (with our own twists):

1. We want to make this anchor chart from "The Classroom Key" (one piece of it each day).

http://theclassroomkey.blogspot.com/2014/04/part-part-whole_9.html

Our week will start off with a review of our hula hoop activity....but with chenille sticks and beads.



2. We want to show "whole-part-part" with plates like Dr. Jean.

http://www.drjean.org/html/monthly_act/act_2011/01_Jan_css/pg02.html

3. Just another way to show "whole-part-part" but with hangers (can't find original source.)



4. We also want to do an activity with cubes.  Each kid will have two different colors to make a part-part-whole equation.


 
 I think it is going to be a fun week!  But do you have any other suggestions?  We are ALWAYS looking for more ideas!!


6 comments:

  1. Theoretically, there is no such thing as subtraction - it is merely the addition of inverses. So teaching them simultaneously is really optimal. Instead of saying "adding" or "subtracting" you can use "togetherness"...

    We're putting 2 things and 3 things together. Or, we're making 5 things not be together anymore.

    Great experimentation!

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    Replies
    1. This is great!! Thank you! We will start using these words right away. We have been saying that for addition but I will make sure I add that for subtraction.
      Em

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  2. I think my kiddos would like these activities! Thanks for sharing :)

    Amanda

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  3. You are getting me so excited for teaching math! I can't wait to use the Hula-Hoops next week. We "start" subtraction next week in our math book, but we've been talking about it and practicing it without using symbols. Next week we start recording with numbers and symbols that relate to subtraction. I'm thinking now about using Bon's ideas and "Togetherness"!
    Jenny

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  4. Easy the most brilliant way to make this happen! I love all of the small versions (coat hangers and pip cleaners) that kids can come back to after the main hoola hoop lessons. Thanks for the great ideas.
    CaseyJane
    WigglingScholars

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  5. I am also headed into my unit on subtraction/addition this week. I am teaching them together for the first time. I want to add a lot of problem solving to this discovery. I will create situational stories using their names and little toys I purchased. During our number talks I will record the strategies they used for solving. I am excited and ready to kick this off. I love your ideas as well and will be including these into our discovery and exploration. Thanks for sharing!

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