Do your kids struggle with multiplication? Do you pull your hair out when you have to teach it? Maybe this method can help.
When I was in junior high, I discovered a different way to do multi-digit multiplication. I honestly can't remember what book I read, or where I learned it, other than I know it wasn't what was taught by my math teachers.
But as soon as I taught myself the method, I was hooked. I switched completely to using that new method and never looked back.
The partial products methods (although at the time I learned it, I had no idea that's what it was called) improves on the traditional method of multi-digit multiplication in two main ways.
- All multiplication is done first, then addition at the end. The current method requires the student to switch back and forth between multiplication and addition. Keeping each operation together prevents errors in calculation.
- Rechecking work is quick and easy since the products of each pair of digits is visible in the process of working out the problem. This simply isn't possible with the current method.
My own children use the partial product method when they multiply, and they like that they can recheck their own work without having to totally rework their problems. I like it as well because when they make an error in their work, I can see quickly where in the process they went wrong.
The easiest way for me to share exactly how the partial products method works is to show you, so I've made a short video explaining the method. If after watching the video you have any questions about it, please ask. I'd love to help explain it further.
Personally, I think it would be fantastic if this method were taught in the mainstream of math education as a primary method rather than an alternate (if it's even taught at all). I think the partial product method is far superior to the traditional method of multiplication that is taught now and that children would suffer much less over their math homework if they learned this method.
Maybe next week I'll share how we do short division. (Long division is a four-letter-word in our house).
{ 17 comments… read them below or add one }
Oo I like it!
We're only working on multiplication facts this year in 2nd grade…..do you use this with a certain curriculum? Or just incorporate it with whatever you have?
We'll be using Math on the Level this year.
Thanks for sharing!
blessings,
Nikki
NIkki´s last blog ..Are you Necessary to Somebody?
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@NIkki, We didn't do this with any particular curriculum. I just taught this method whenever my kids were introduced to multi-digit multiplication in their math curriculum in lieu of the way they were being taught in the curriculum.
When I first taught it, I used zeroes as placeholders, like the traditional method does. I quickly came to realize that using zeroes was a bad idea. If one of your partial products ends in a zero already, it can be confusing to also use a zero as a placeholder. Therefore, I switched to using a dash instead. It made things SOOOOO much easier, preventing errors, and making rechecking even easier since the actual products were highlighted in the work.
I do show my kids the difference between my method and the traditional method so they know why their book shows something different. But I've never made them practice doing the traditional method, just understand why it looks different.
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Most excellent! Thank you for taking the time to explain it.
~Shannon
Shannon´s last blog ..Bless your cherry pickin heart!
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And no one shared that with my in my teacher ed classes why???!!!
Amy @ Finer Things´s last blog ..Mommy, Come Home: Gratitude for the Veteran SAHM
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Joy, this is wonderful! I am definitely going to show this to my kids. Thank you so much.
Kristen´s last blog ..Chore Chart
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Makes sense to me! It really does make it easier to check. I just showed the video to my 10 yr old however and he doesn't get it. But I think I'll have him try next time we do multiplication in his math book.
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The Everyday Math curriculum uses several alternative algorithms.
http://www.nychold.com/em-arith.html
I teach the division one in a course for teachers that I teach (partial quotients). You can search youtube and find videos that match up with the everyday math approaches.
Michele´s last blog ..Balancing Act
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I love it! Much much better than the old way.
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My hubby has a degree in mathmatics and has been a math teacher for the last ten years. I sent him this video and he says- and I quote, "This is GENIUS!!!!!"
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I LOVE this!!
Phoebe @ Cents to Get Debt Free´s last blog ..Corn Cob Jelly Recipe
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Amazing! Thank you!
Smockity Frocks´s last blog ..Finer Things Friday
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Genius! I have struggled with math (especially multi-digit multiplication) in school for years! This method is going to make teaching SO MUCH EASIER! and we can check the work to see the weakness, amazing! Thank you for sharing!!!
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Thank you so much for sharing. My ten year old loved watching the video. I loved watching him breeze through his multi-digit multiplication problems. I can't wait to see the "short division" video.
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How do you do short division?
-Phyllis
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joyfulmiller Reply:
January 23rd, 2010 at 10:04 am
@Phyllis, It took me a while, but I finally posted my short division video here: http://fivejs.com/a-better-way-to-divide-short-division/
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Joy, thanks for the video. My son had partial product on his homework worksheet tonigh and I had no idea how to explain it to him. I am bookmarking your site for future reference. Thanks for helping us "old school" parents out. I can't say this method is easier because I learned the old way and it works, but now I know a different way and hopefully will be able to help him master this method now.
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I just wanted to let you know that we have been using the partial product method at our house with much success. I have written a blog entry about it and am sending people over to see your video.
Thanks for posting this!
-Phyllis
http://homeschooljournal-bergblog.blogspot.com/2010/01/partial-product-method-of.html
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ooh! THANK YOU! I kinda *saw* this when doing multiplication with my daughter recently and we started trying to work it out on the dry erase board and we really botched it so I said, "okay, nevermind, forget all that, go back to the old way."
Now I see that this really can work. Thanks again!
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