SamizdatMath

Are you teaching the quadratic formula to your students? Are you teaching it the same way you learned it in high school? Or maybe college? Or maybe on the street somewhere? Then you're probably teaching it WRONG AF. It's okay: I've been teaching the quadratic formula WRONG AF for decades. I didn't know it, but I was. It wasn't until one day I was working with a group of my college students and made a mistake that I had a realization: we've been teaching the quadratic formula WRONG AF for decades

This is a collection of 36 factor riddles to help your students prepare to factor quadratic equations.

This is the best investigation you can find anywhere which links exponential growth with paper folding. It includes background information about the investigation, and uses charts and tables to keep track of how tall a piece of paper would be if you folded it in half up to 60 times. The activity works with both customary and metric units and has answer keys for both. This investigation also looks at the formula that was derived by Britney Gallivan, a high school junior who actually proved that

Here's another mathematics investigation straight out of the SamizdatMath laboratory. Yes, the same place which brought you " How to Hack Your Burrito," " What's the Best Way to Fit a 15' Fishing Pole in a 10' Box?" AND "WTF is Survivor Bias and Why Should I Care About It?" now brings you a complete investigation into the age old problem "what's the fastest way to cook 3 steaks in a pan that only holds 2 at a time?" This is a problem that has been circulating around, and it has a fun solution,

First of all, it should not be called the "Pythagorean Theorem," because Pythagoras had nothing to do with inventing or discovering it. The Chinese knew about it hundreds of years before, and the Mesopotamians? Like 1300 years before! Zip Zap.... Okay, this is a really REALLY cool activity that uses the "Pythagorean" Theorem to solve a very important question: how can you ship an 11 foot fishing pole, when the shipping box can't be any more than 10 feet in length? Take some time to scratch you

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

This is a collection of 12 different division reasoning problems that require your students to understanding through written explanations. No, it doesn't mean your students are going to explain the long division algorithm by writing about the steps they took to solve the problem. First of all, who cares? Second of all, it doesn't really show a mastery of the concept of division; it only shows they have memorized the steps in an algorithm that is totally unnecessary to memorize in an age of calcu

This is the most carefully and completely documented use of the "The Handshake Problem" (also known as the "Glass Clink Problem") that you can find. It spans 5 days worth of lessons, homework assignments, enrichment and an assessment. The beauty of the "handshake problem" is that it can be looked at as a way to represent a problem visually through the use of points and connecting edges, but it can be investigated as a sequence of triangular numbers. This is then be compared to other types of seq

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

"STOP THAT ZOMBIE! is a truly "hands on" approach to working with addition and subtraction, with links to algebra, patterns and problem solving. The basic puzzle is simple: using the numbers 1- 6, distribute them around a triangle so that each side adds up to 9 (thus, trapping the zombie in his cage!) Where it gets really cool is this: you can arrange those same 6 numbers to add up to 10, 11, and 12 on each side. But the fun doesn't end there: you can differentiate this by using the numbers 2 -

We are reflective teachers who embrace the CCSS Standards for Mathematical Practice. We are committed teachers who want to take the magic out of mathematics and focus on the beauty of sense-making. We wish for teachers everywhere to seek coherence and connection rather than offer students memorized procedures and short-cutting tricks. Students are capable of rich conceptual understanding; don't rob them of the opportunity to experience the discovery of new concepts. We acknowledge that this is

"Trap That Turkey" is a truly "hands on" approach to working with addition and subtraction, with links to algebra, patterns and problem solving. The basic puzzle is simple: using the numbers 1- 6, distribute them around a triangle so that each side adds up to 9 (thus, trapping the turkey in the pen!) Where it gets really cool is this: you can arrange those same 6 numbers to add up to 10, 11, and 12 on each side. But the fun doesn't end there: you can differentiate this by using the numbers 2 -

Stop That Rat! ? Why would anyone want to "stop that rat?" Well, because it's really fun to watch your students work on this puzzle, which comes in gritty color as well as black and white. 63 pages of rat fun! Seriously, the basic puzzle is simple: take the disks which are numbered 1 - 6, and arrange them on the board so that each side adds up to 9. However, things get very interesting when you find out that you can re-arrange the 6 numbers to add up to 10, 11 and 12. But it gets better than th