Maybe you’ve seen several of the Common Core math problems making the rounds on the internet lately, prompting adults (parents, writers, teachers, what have you) to point out how the methods contain unnecessary steps which complicate basic procedural skills such as addition and subtraction. Having students draw diagrams and create “T charts” when solving a simple arithmetic problem just makes it more confusing, they claim, when all students really need to do is know how to “carry the one” to solve the problem accurately.
Such critics overlook the importance of having students understand why a mathematical concept works—not just that a mathematical concept works. In fact, having a deeper understanding of math is incredibly useful both in and out of class.
Here’s an example:
The “old way” of calculating 2000 – 1999 would involve a lot of “borrowing” to arrive at the correct answer of 1. But the “new way” would just as soon see kids turning the problem around into one involving addition: 1999 + 1 = 2000. This flexibility of mind becomes essential later on in, say, algebra class when the student is balancing equations and must approach each problem creatively.
And this type of thinking has real-world applications, too. Say, for example, you’re at the hardware store buying a packet of seeds for your garden. The seeds are $3.70 (tax included) and you hand the cashier a ten. How much should he give back? The old method would require you to take out a piece of paper and write this:
The new approach would encourage you to round up to four dollars (by adding 30 cents) and then calculating the difference between 10 and 4. So you should be getting 6 dollars and 30 cents change, a simple calculation you can do in your head…no borrowing needed.