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Why does my 11 yo ds have trouble with double digit


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ummm ....

 

He gets stuck when he carries a number. If the problem was

 

532

x 26

--------

 

 

he would multiply 6 x 2, put the 2 down and not know where the 1 goes. I've had him use notebook paper turned sideways so he has columns, which helps a little. The blocks used with MUS just confused both of us. How do I know which math curriculum would be best for him? Khan Academy videos help, but he needs an actual curriculum that makes sense to both of us

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A couple thoughts:

 

Can he carry in addition? Because it's basically the same principle, and pretty much the same procedure - put extra tens over the tens place, extra hundreds over the hundreds place, etc.

 

Can/could he do multiplication without carrying? Like this:

__532

x__26

___12 => 2x6

__180 => 30x6

_3000 => 500x6

___40 => 2x20

__600 => 30x20

10000 => 500x20

13832 (hope that's right, did it really quick, no checking :tongue_smilie:)

 

Might show if it's a place value issue, or just a keeping the numbers straight issue.

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Also, wrt finding a curriculum that you both understand, I'd figure out which ones make sense to *you*, and then let him pick from those.

 

You've said that neither MUS nor TT have worked out. You mentioned the blocks in MUS confused you both, but what were the problems with TT? Also, did you like how *you* learned math as a child - if so, maybe you could describe what you liked about it and the Hive could see what programs are similar. And if you *didn't* like how you learned as a child, what didn't you like about it? And do *you* feel confident about teaching math and your math education in general, or is it a weak area?

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Here is a sample lesson from MM, though I suspect there may be valuable applicable stuff that comes before it in the Multiplication 2 booklet.

http://www.mathmammoth.com/preview/Multiplication_2_Multiplying_3digit_by_2digit_Number.pdf (or maybe have him look at multiplying 2 digits x 1 digit first http://www.mathmammoth.com/preview/Multiplication_2_Multiply_Columns_Standard_Way.pdf)

 

and the corresponding MM video http://www.youtube.com/mathmammoth#p/u/16/dDQSzMEKfYs

 

(if this turns out to be helpful, please let me know, as I am heavily leaning toward purchasing MM but I'm having cold feet)

Edited by wapiti
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ummm ....

 

He gets stuck when he carries a number. If the problem was

 

532

x 26

--------

 

 

he would multiply 6 x 2, put the 2 down and not know where the 1 goes. I've had him use notebook paper turned sideways so he has columns, which helps a little. The blocks used with MUS just confused both of us. How do I know which math curriculum would be best for him? Khan Academy videos help, but he needs an actual curriculum that makes sense to both of us

 

Most math curricula seem to carry the 1 above the next digit to be multiplied in the problem itself. In contrast, I was taught to carry the 1 above the blank space where I was going to write the next digit of a product, that the 1 was added into (does that make any sense? it's hard to describe). I always thought my way makes more sense :D, though I haven't been able to convince any of my kids yet.

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if this turns out to be helpful, please let me know, as I am heavily leaning toward purchasing MM but I'm having cold feet

 

The single-topic "blue" Multiplication 2 worktext is awesome! I bought it after looking through Singapore 3A and the HIG & realizing there was no way in heck my DD was going to be able to make all the conceptual leaps required. Maria Miller's explanations are superb and I really liked how she breaks it down step-by-step-by-step for the student. She takes the child in gradually rather than Singapore's approach of simply tossing him/her into the deep end of the pool.

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ummm ....

 

He gets stuck when he carries a number. If the problem was

 

532

x 26

--------

 

 

he would multiply 6 x 2, put the 2 down and not know where the 1 goes. I've had him use notebook paper turned sideways so he has columns, which helps a little. The blocks used with MUS just confused both of us. How do I know which math curriculum would be best for him? Khan Academy videos help, but he needs an actual curriculum that makes sense to both of us

 

When my kids learned multiplication of double digit numbers, the book emphasized that they were multiplying times ones then times tens. It had expanded notation that looked something like 532 = 500 + 30 + 2 and 26 = 20 + 6

 

I think the multiplication would have been written:

(500x20 + 30x20 + 2x20) + (500x6 + 30x6 + 2x6)=

(10000 + 600 + 40) + (3000 + 180 + 12)=

10640 + 3192 =

13832=

 

What you might want to do is back up to problems like 532 x 6 = 500x6 + 30x6 + 2x6= for a while to help him remember what the algorithm represents.

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Maria Miller's explanations are superb and I really liked how she breaks it down step-by-step-by-step for the student. She takes the child in gradually rather than Singapore's approach of simply tossing him/her into the deep end of the pool.

:iagree:

Maria Miller is absolutely brilliant at explaining complex math concepts in a way that kids totally get, without either dumbing them down or forcing kids to "connect the dots" themselves.

 

Jackie

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As far as TT goes, I liked it and my son liked it but he didn't retain anything he learned. I do not feel comfortable teaching math. I learned multiplication of multi-digit numbers the old fashioned way and it didn't seem very difficult to me, carrying numbers was easy and I'm not that great at math so I don't understand why my ds has problems. He is actually starting to get it because I've been making him watch the Khan Academy videos over and over and work the problems.

 

I need a curriculum with plenty of repetition and I need videos or a really clear explanation of how I'm supposed to teach each concept. Would Khan Academy videos and MM work together?

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