# Ever see this before?

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The neighbor kid just asked me to check his math homework, and I've never seen an equation like this before. Is this new math, or am I just out of the loop? :001_huh: We've been using RightStart so it might just be me.

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The first one looks like a pretty straight forward subtraction problem to me. The second one just has you adding the pieces for each child.

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are you talking about the little number line thingys?

Basically, they teach the kids with number lines to break up the addition and subtraction problems into easier to solve bits.

I have no idea whether it is new math or not, but K12 does this with their 2nd grade math and, while it would be good in theory to teach a variety of adding/subtracting strategies, my daughter got so confused when she was given 5 different methods of solving one problem. Especially, given that she already completely understood how to do it the "old fashioned" way, using borrowing and carrying.

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The neighbor kid just asked me to check his math homework, and I've never seen an equation like this before. Is this new math, or am I just out of the loop? :001_huh: We've been using RightStart so it might just be me.

#2, yes?

The kid is playing around with 37 being 3 less than 40. He's just made the mistake of adding the three instead of subtracting it.

So he needs to add 37 and 23. 37 plus another 3 is 40. Now you have to add in the 23, but you've already taken the 3 to make your 40, so you just add the 20 to the 40 and get 60. Ask the kid how his notation is supposed to work, and if he understands it he will probably realize his mistake.

See how he did #1.

So 53 is 7 away from 60. It takes 40 more (from 60) to get to 100. However, you have to remember to add the 7.

I think the notation is kind of like Cuisinaire rods but without the rods. He has to be clear how he notates stuff that needs to be added to the next step and stuff that needs to be subtracted.

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Shoot, I'm 48 and the nuns taught us using number lines. So chances are, it's nearly ancient math. ;)

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That's an Investigations math worksheet, as far as I can tell from the colors and content. Investigations (at least the way our district taught it) is the reason that we left public school.

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my daughter got so confused when she was given 5 different methods of solving one problem. Especially, given that she already completely understood how to do it the "old fashioned" way, using borrowing and carrying.

This happened to my DD also! Have you seen that "lattice multiplication" they teach as an option? What a mess...

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are you talking about the little number line thingys?

Basically, they teach the kids with number lines to break up the addition and subtraction problems into easier to solve bits.

Yes, they are number lines. We used them when I taught ps 25 years ago. . . so no, they are not new.

BTW - I didn't actually check the accuracy of his math.

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This happened to my DD also! Have you seen that "lattice multiplication" they teach as an option? What a mess...

What is frustrating is that the curriculum expects the kids to learn each method and be tested on it. "Add these numbers using the x method" "Subtract these numbers using the x method" Rather than presenting these all as options and saying "Use the one that works best for you!"

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With the first problem, I can see how he came to that conclusion. But 2? I'm not quite sure what's going on there. My six-year-old would solve the problems with number bonds and addition or subtraction.

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What he said is you make a line. On the left side is the number you are starting with, and the other is the goal. Back to the left, you make a dot and write the number to the nearest tenth, and inside the loop you say how many ones it took to get to that number. Then you make a big loop from that tenth to the goal, and write the difference inside the big loop. Then you add the two loop numbers together to get the answer. (If I understood him correctly)

I don't have anything against using timelines, I love timelines! But this seems kind of convoluted to me. Then again, we're using an abacus in RightStart and learning math an entirely different way than how I was taught in school. So what do I know. :tongue_smilie:

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Isn't it basically the same as the bars in Singapore math?

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