SamizdatMath

Here's the problem: There are 100 seats on an airplane and 100 people waiting to get on. The first person loses their boarding pass, so they take a random seat on the plane. If the next person finds their seat occupied, they take another random seat. If their seat is free, they sit in it. Question: What is the probability that the 100th person on the plane will sit in their assigned seat? Oh, sure, you can look up the answer and come up with some convoluted or excessively mathematical explanati

Teach your students the importance of ratios and unit rates.

This is a winter themed variation of Silly Creatures Number Logic Puzzles, a fun little booklet that your students can put together in about 3 minutes and features 2 kinds of objects to decipher. This version involves three different objects to interpret, which will really give them something fun to do and most likely fry their brains by working logically - and because this is something you purchased from me, your kids will also have a chance to make their own puzzles to share with one another.

Note: this is the same as the "winter theme three part number logic puzzles," but with "silly icons" instead of "winter icons." This is a sequel to Silly Creatures Number Logic Puzzles, a fun little booklet that your students can put together in about 3 minutes and features 2 kinds of objects to decipher. This version involves three different objects to interpret, which will really give them something fun to do and most likely fry their brains by working logically - and because this is somethin

These are four puzzles that explore the issue of parity, which has to do with the "evenness" and "oddness" of a number. The first two puzzles involve "visual parity," which has to do with how two colors or shapes "match" up to one another. The second two are puzzles that involve numerical parity, neither of which has a solution due to the nature of odd and even numbers. They come in poster form, or you can print them out 4 to a sheet a leave them around for your students to puzzle over. Include

This is an old brain teaser that someone told me, and which I shortened and clarified, as well as added clues for your students to use, as well as three different explanations for how to solve it. Basically, the problem goes like this: you have 7 people who want to find the average of their salaries. The only problem is that no one wants to tell anyone how much they earn. How will you find the average without anybody stating their actual salary? I've run this problem by all my techie type frie

This is one of an occasional series of mondo-tough problems that use small numbers (or no numbers at all!) Here’s how it works: we all teach our students how to take a group of numbers and calculate the range, mean, median and mode. Seems pretty simple, and our students tired of it damned quickly. Can you blame them? It’s just “do what the teacher told me to do, and then write the answer here...” kind of busywork. But what if we were to switch the tables on our students: let’s give them t

Here’s the idea: your students are learning about coordinate geometry, so you teach them hoe to find the x and y axis, they plot a few points, maybe you play some lame games, and then they’re off and graphing some equations. Bo-ring! These activities teach students about the conventions of coordinate graphing (they are not “rules”, they are “conventions”) and then applies them to the practice of solving actual problems, from delivering pizza to making maps to guide first responders. The activiti

You see those gift cards hanging on the rack near the checkout counter? Well, they're a total ripoff, and this activity will show your students once and for all why they should just never, ever buy them. And maybe you won't either! Using a listing of 4 different values of gift cards from a popular "big box" store (whose name shall not be named here, except for the fact that they pay their employees substandard wages, prevent them from unionizing and then encourage them to go on food stamps....)