Painting Puzzler – Car Talk

I never could remember how to solve these type of questions. RAY: Tommy, Dougie and I are sitting around the office one day at Car Talk Plaza. We were noticing how dingy the place looked. We’d been there 15 years, and the place had never been painted. So, we decided to paint Car Talk Plaza. […]

First Day Activity: Puzzlers

On the first day of class in AP Calculus and Pre-Calculus Honors I’ll give out the following list of puzzlers that they’ll have a limited amount of time to work on. The students will be working in groups on the new $2 interactive whiteboards. Google Doc link. PDF link. Btw, I still haven’t figured out […]

The Love Tree – A Math Puzzler (?)

From Car Talk. A teenage boy smitten with a teenage girl in his high school freshman class, made his feelings known. Overjoyed at finding them reciprocated, he took pen knife to a young hard wood in the vicinity and carved their initials within a heart, five feet up the tree’s trunk. By their senior year, […]

Dr. Square

Much like the Collatz conjecture, the Dr. Square Puzzle (from the blog mathforlove) is an intriguing problem. With some playing around, we came up with what I think is an excellent (and solvable) puzzle. He dubbed it the Dr Square puzzle, because it involves one of the steps in taking the digital root (dr) and squaring numbers. Here’s how it goes. […]

Puzzler : 20,000 Lights

From Car Talk. RAY: This puzzler is from my “ceiling light” series. Imagine, if you will, that you have a long, long corridor that stretches out as far as the eye can see. In that corridor, attached to the ceiling are lights that are operated with a pull cord. There are gazillions of them, as far […]

Cartalk Puzzler – Stone Temple Farmers

From Cartalk. Stone Temple Farmers RAY: A farmer had a 40-pound stone that he could use to weight 40 pounds of feed, hay, or whatever else he wanted to sell from his farm. He had a balance scale, and he put the stone on one side and piled the other side with feed or hay, […]

Little Gauss and the Dividing Time Puzzler

I gave this problem to the Precalc Honors class, right before their lunch (the block is split into two parts). A couple of them came back with the solution, but most had chosen to eat and socialize (how dare they!). An epiphany hit me when I saw how a student had started to solve the problem. […]

Cartalk Puzzler – Dividing Time

From Cartalk. Dividing Time RAY: Draw a clock face on a piece of paper. Using Arabic numerals put the appropriate numbers at 12, 1, 2, 3 and so on. Now, somewhere on the clock face, draft two lines. In doing so, you’re going to divide the clock face into segments, which contain numbers. TOM: Do […]

Dartboard Problem

From Infinigons, etc: Putting myself in kids’ shoes You have a square dartboard. What is the probability that a randomly-thrown dart will land closer to the center of the dartboard than to an edge? Superb problem. I took the lazy route. I made a python program to run 100,000 trials, and graph those trials on a […]