Monday, August 4, 2008
Family issues
When teaching children in 1st grade the concept of the "fact family", where the numbers 10, 8 and 2 are a family, I have found that the addition facts can be generated, but when they have to create the subtraction facts they don't always use the greatest number first, which is the "rule"! After doing the exercise today with 3x4=4x3 I have been trying to think of a way to visually demonstrate this concept and to use better language, (is there a better term for subtraction, take-away or minus?) I am new at this and the answer may be blatantly obvious... but that's ok.
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Can you comment on your own blog? I think I should have read the Chronicle article first!!! Maybe if I introduced the = symbol and worked on the idea of balance a child would get the subtraction concept better???
This is just what I was going to say, Susie! The article reinforced the idea of balance. Also, as students write the subtraction incorrectly, ask them to show you what they mean with manipulatives. Perhaps by reinforcing their error (and the concept of does not equal), they will be more in tune with how they write the fact in the future / better understand the concept behind the fact family.
Sounds like you've experienced an "aha" moment here Susie! I think you're on to something... using manipulatives and the balance should really help your students taste the mango.
:-)
Cindy N.
Sorry...just wanted to make afew changes...
After reading the article...and thinking about how your students (and mine) don't always connect the relationship between addition and subtraction, I had my own “aha” moment with the “/”. I understand that it means "not" or "opposite"…the plus sign + is "not" subtraction or is the opposite of it. Multiplication is the opposite of division, X is just a division sign with a slash through it. This lends to teaching these operations together, rather than in isolation. Like Maggie states in the article, “…you have to know ‘up’ to understand ‘down’.”
I do tell my students these operations are related as opposites, but I love the idea of relating it to other common signs to reinforce “not” and “opposite”. Just another strategy to explain these concepts…Perfect for ELLs!
Once you've established the concepts of simple addition, simple subtraction, and what "equals" means, you might try this visual idea for demonstrating the relationship between addition and subtraction: Have a child place 8 stickers on one square of paper and 2 stickers on another square. Addition is demonstrated by placing the squares together. Have the child fill in the missing words as you state,"We started with__stickers and added__stickers. Now we have__stickers." Then put symbols in place of the words: 8+2=10. Switch the papers' positions and repeat to show 2+8=10.
Subtraction is demonstrated by starting with the two squares together (which makes 10 stickers) and then taking the 8-sticker square away. Have the student fill in the missing words as you state, "We started with__stickers and then we took away__stickers. Now we have__stickers left." Then put symbols in place of the words: 10-8=2. Put the squares back together and repeat the same steps as you remove the 2-sticker square.
Then have them try a different fact with a partner. Some kids need more practice than others to grasp that relationship between addition and subtraction. I hope this helps.
Well now... this thread is very interesting. I won't respond to it right here as this is the very topic for Wednesday, but I want to let you know that your questions and comments reflect an age old problem common to us all. Believe it or not, the answer to this dilemma is extremely simple and natural. Until Wednesday!
Well now... this thread is very interesting. I won't respond to it right here as this is the very topic for Wednesday, but I want to let you know that your questions and comments reflect an age old problem common to us all. Believe it or not, the answer to this dilemma is extremely simple and natural. Until Wednesday!
Well now... this is a perfect example of a rich blog thread. We have questions, insights, support and sharing all in one. Well done! I won't respond to it right here as this is the very topic for Wednesday, but I want to let you know that your questions and comments reflect an age old problem common to us all. Believe it or not, the answer to this dilemma is extremely simple and natural. Until Wednesday!
Well now... this is a perfect example of a rich blog thread. We have questions, insights, support and sharing all in one. Well done! I won't respond to it right here as this is the very topic for Wednesday, but I want to let you know that your questions and comments reflect an age old problem common to us all. Believe it or not, the answer to this dilemma is extremely simple and natural. Until Wednesday!
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