subtractionSo here is a common core math sheet from back when Brandon was just learning to subtract 2 digit numbers. The instructions:

“Use the numbers in each jellyfish to  make a subtraction problem.  Check by adding.”

It expected him to work out the logic of knowing that they first needed to start with the largest number at the top, then make sure they subtracted the next largest number in order to make the problem work to get the smallest number last. No instructions on the sheet about even trying to explain the logic. I asked Brandon if they had been doing this type of work in class filling out the boxes or dealing with why the larger numbers would go on top etc. and he said no. Knowing what level of math problems we had been doing at home, it was clear they had pretty much just learned about borrowing for simple double digit subtraction.

Next in the first example they needed to take the last number (presuming they correctly filled in the first three boxes), move it up to the top box of the addition problem and then leave them to try to figure out which number would go into the second box that would equal the last box. Obviously this could be done by trial and error and explained with some help by a parent, but it doesn’t teach them the “why” or reinforce something they have been learning at school. How many kids across this country don’t have a parent who is helping along side nightly at home to help explain this logic? That should be a big factor for these take home sheets. They should primarily reinforce what is being taught in the class.

Had this work sheet been a couple months after learning double digit subtraction I would understand that they should hopefully have enough of an understanding about the logic behind how the numbers relate, but this is what was being used to teach the core principles of how to work a double digit, simple level subtractions problem. From this and the other shared examples I’ve seen being shared online, (see this link for a great example) there seems like there is this overshadowing desire to try to get the kids to think abstractly about how to get their answers. These types of principles should be taught only after they have a primary understanding of the basic “mechanics” of the type of math they are learning. This is really going to mess up their problem solving skills later. When they need to do a type of math to solve a problem, they are sure to find situations where these fluffy abstract visual methods are not going to be able to be applied and it’s going to create a mental hurdle for them to get over. They will have to learn a new way to think about how to do the same problem yet another way instead of the simple basic method that have been used for centuries that can be applied to almost anything. Is the original style of subtraction still being taught. Sure it is, we have seen those worksheets too, but it’s a big gap between those and this sheet.

Don’t hear what I am not saying. I like the idea of common core. Having a national standard of work to be done and learned that we can study the results of and adjust slowly over time as needed to improve learning as a whole is smart. I think is a good idea. And think of all of the indoctrination and history re-writing that could be taught all across the nation with common core 😉 but that’s another battle to be had later.

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