re: 9+6 = ? "Our young learners might not be altogether comfortable..."

I know this thread has died and has been dead for a couple days but I want to resurrect it anyway.

I saw this story on my Facebook feed this morning and I wanted to comment.

First this math actually works. It is many times the way I do this. 7+6 , in my head I do (7+3) + (6-3) = 13. It is a good thing to do it this way. I'm fine with this.

Now this adding problem is no big deal but than I started to look into common core math and it started to PISS ME OFF.

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this first video tries to explain a "better way" to subtract 87 from 243

typically we would do it this way
243
-87

Stack numbers.
Subtract 3 from 7 which gives you - 6
because you you have a negative number you must take 1 away from 4.
3-8 is -5.
Same way make 2 1.
gives you 156.
If I actually did that by hand I would take me 5 to 10 seconds.

Now the way common core does it.

you draw a number line. (takes 10 seconds)
mark the number you want to subtract by on the line.
mark the number that will get smaller on the line.
now round 87 up to 90 and mark how much you have to add
round up 90 to 100 and add how much you have to add.
add 100 to 100
add 43 to 200

add all of the numbers up that you added up when rounding

100
+43
+10
++3
____

now there are more steps to get this.

add 0+3+0+3 = 6
put that number down
add 0 + 1 + 4 = 5
put that number down before 6
move the 1 down in front of 56

you now have 156 which is your answer.

So the old and quick way took me 6 steps
The new way took me 11 steps.

Rules I must remember for subtracting

1) if the number I subtract by is bigger than the number that gets smaller, I must take away the top number on the next set. (for example 3-7 is less than 0 so you must take away a number from the 10th place in order to for it to work.
2) I must line up the numbers so that, the 1s line up with the 1s. The 10s line up with the 10s, etc.
3) now do simple subtraction.

Rules for new math.

1) I must round up to the 10ths place
2) than the 100th place.
3) I Must write down each time I round up
4) add 10s or 100s to make it to the other number
5) once you make it to the closet 0s number add what you have left.
6) take all of the numbers you use to add up to get to the other number and add them.
7) if two numbers add up to be bigger than 10, only put the single digit number down and put a 1 over the 10th place.
8) IF you carry a number you must add it into the next equation.

so 3 rules vs 8 rules.

I don't see how the new math is easier.

BTW the guy in the video is an idiot. It took him three tries to get a very basic math problem figured out.

Plus it isn't easy to remember 3 rules when subtracting. The new math doesn't take out basic math, it just adds more steps to apparently make it easier. Also if you an accountant and you have thousands of numbers to add up. Do you think that doing it the new way would help you keep your job?

Here is another example of what I just explained above.

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A very easy subtraction problem, made complicated.

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here is another video (slanted against it) trying to show why it is worse.

Now I understand what the teachers are trying to explain. They are trying to visualize it for students. Which is fine. This is where I have an issue. A 4th grader may not understand why he has to carry a 1 to the next set of numbers when you first show it to them. This may help them. Hopefully you only have to show that once or twice, once they understand the concept you simplify it so that it can be done quicker. Common core can help describe why we do it, and why things work the way we do. The old math is the efficient way to do things, just doesn't do a good job of explaining why it works that way.

last video I promise

this one pisses me off the most.

LINK