However, one should be careful to not condemn any school material in a knee-jerk way. For example, Erick Erickson of RedState complains about a method of subtracting one number from another.
“The picture… [below] is from my third grade daughter’s math book. This is the only page that explains that method for subtraction. There are, for the record, four ways to subtract that my third grader must learn.
“This is the only page explaining that method. This is the only example. The very next page goes to arrays. The page after that goes to multiplication. This is it.
“The traditional method of subtracting, borrowing and carrying numbers, is derisively called the ‘Granny Method.’ The new method makes no freaking sense to either my third grader or my wife.”
First and foremost, I wholeheartedly agree that the “Granny Method” should be the first method taught. It is straightforward and easy to master, even if you don’t grok all the finer points. It allows a student to get a feel for subtraction. Once they know how to do that, they will be better able to understand short-cuts and tricks… which is exactly what that above assignment is.
The method is not a bad one, and can be easily done on the fly in one’s head. It simply allows one to determine the difference between the two numbers, since the answer to any subtraction question is ultimately just the difference between the two numbers. The method actually does make sense, and is easy to do in one’s head.
There is much to despise about Common Core. This is not one of them.
Hat Tip: Hot Air.