POSSIBLE WEEDS TO PULL: TEACHING
GENERALIZATIONS
There are many generalizations we learn in Mathematics classes as young students, that do not translate, as we learn higher level Math. One of these generalizations is “You cannot take a bigger number from a smaller number.”
We are taught, as we learn to subtract, to always subtract the smaller number from the larger number. This statement will not always be true. As children progress through Mathematics, they learn about interesting new numbers. These new numbers are called integers. When integers are introduced, children learn that indeed you can have a number that is less than zero. This is very confusing to children who have been taught that you can’t subtract more than you have to begin with. As an example, let’s look at the following problem.
Tom has 13 donuts and John has 12. Tom ate 6 donuts and John ate 15. How many donuts does John have now?
John ate more donuts than he had. The confusion is how John could eat more donuts, than he had at the beginning of the problem. Students, under the Mathematical Practice Standards, are able to discuss the possibilities. These standards are designed to assist students in the use of their logic and problem solving skills, rather than learning rules and applying them.
I learned about negative numbers at a very early age. I was unaware of it at the time, however. I began playing card games with my grandfather, at the age of 4 or 5. In fact, he “created” a game, just for us to play. If Grandpa went out before me, I had to figure out my score. My score was dependent on the cards played against the cards still remaining in my hand. Sometimes, I had sufficient “points” on the board to cover the “points” remaining in my hand and sometimes not. If my hand had more points in it, than I had played, then either I “went in the hole,” on the first hand of the game, or “went” back that number of points. It was even possible to go in the hole, if my score, from the previous hand was not large enough to consume the points remaining in my hand.
I enjoy playing cards. There are many games that children can learn to play thatwill teach many mathematical principles. This would allow children to learn more about how numbers work with each other, even if there is no real understanding of the concept at the time. While playing cards with Grandpa, I didn’t realize I had utilized negative numbers, nor that I could have less than zero. However, I did understand I had to get enough points to “get out of the hole.” This is the concept of integers and negative numbers with no real “hard and fast” rule attached to it.
I can also remember, in Algebra II, learning about systems of equations. The problem we were solving required us to calculate the number of adult and child tickets sold for a play. As we, the entire class and teacher, worked out the problem, one of the solutions was a negative number. My teacher said, “You can’t have negative money, so that answer can’t be correct. The correct answer is the positive one.” I was stumped. You certainly can have negative money. However, I understood her statement.
It is interesting that teachers continue to make these types of statements to their students. As I have gotten older, I have learned that it is more important to be able to problem solve and “work through” a problem in my own way, than to adhere to any “rules” uttered by my teachers. I have always excelled at math. I am not as confident or fluent in math theory. I like numbers and playing with them. I am generally lost on number theory. I would have liked a little more theory and problem solving practice, as a child. Abstract Algebra and Nonlinear Geometry may not have been so tough in college. I could be wrong, as both classes are just theory and proof, but may be not. I may have had better problem solving skills.
The Common Core Standards for Mathematical Principles allow students to learn more problem solving skills and strategies. It also gives them the ability to “create” their own and argue for their processes. These skills are necessary to understand number theory. I wish I had had better training early on. As a teacher, I believe using cards and other open ended problems will formulate the practice and instruction I would have liked to have had.















































