The “Aha!” Factor

[Rescued from my old blog.]

For young children, mathematical concepts are part of life’s daily adventure. A toddler’s mind grapples with understanding the threeness of three blocks or three fingers or one raisin plus two more raisins make three.

Most children enter school with a natural feel for mathematical ideas. They can count out forks and knives for the table, matching sets of silverware with the resident set of people. They know how to split up the last bit of birthday cake and make sure they get their fair share, even if they have to cut halves or thirds. They enjoy drawing circles and triangles, and they delight in scooping up volumes in the sandbox or bathtub.

Continue reading The “Aha!” Factor

Finding the Limit

[Rescued from my old blog.]

Eldest dd had her first calculus lesson last night: derivatives. The teacher found the speed of a car at a given point by using the distance function, calculating the average speed over shorter and shorter time intervals. Dd summarized the lesson for me:

“If you want to divide by zero, you have to sneak up on it from behind.”

Of course, she understands you can’t really divide by zero, but I thought her tongue-in-cheek comment was a pretty good description of the process of finding the limit as delta-t approached zero.