SamizdatMath

Back in the 1980s (before most of you were born), the A & W hamburger restaurant chain tried to go head to head with McDonalds' new "quarter pounder" by creating and marketing a "⅓ pound hamburger." It was a spectacular flop. A research company hired to find the source of the problem found out that half of the people surveyed thought that there was less meat in a ⅓ lb. burger than a ¼ lb. burger because, well, "3 is less than 4." The burger was renamed the "Big Papi" and continued to be sold b

This is a collection of ten different four-step mysteries where students have to work backwards (if you'll pardon the pun...) Instead of just taking a number and rounding it off to the nearest hundredth, tenth and unit (which is just soooooo boring and unproductive), the student is given the following clues about a "mystery number" • When rounded off to the nearest unit, the number is 0. This indicates that the number could be anywhere between 0 and .499 - it the number was .5 or above, it w

Did you know that the ninths fractions can easily be converted by taking the numerator and turning it into a repeating decimal? For example, 4/9 = .444... and 8/9 = .888....? Did you know that the 11ths fractions cycle through the 9 times tables through the numerator? 5/11 = .4545.... and 7/11 = .6363.... These are great patterns to know because it can save your students hours of tedious calculations when converting fractions to decimals. Since patterns are the "language of mathematics" then s

These are highly unusual puzzles that are a great way to practice place value while stimulating your students' abilities in deductive reasoning. Each puzzle is set up as an "acrostic" that has to be filled in vertically and horizontally. The "beginner" puzzles are simple to solve, but they are valuable in that they help students to stop thinking of assembling place value by "order" (such as ".8 + .04 = .84," instead of alternating ".04 + .8 = .84") There are 20 different puzzles that use ones a

This is a wonderful activity which uses a real life paradox to explore how ratios change by adding the same number to the quantities being compared. We start with our friend Bud and his nephew Lou. Bud is 40, Lou is 10, so the ratio of Bud's age to Lou's age is 40:10, or 4:1. 5 years later, Bud is 45, Lou is 15, so now the ratio has changed: their ratio is 45:15, which can be simplified down to 3:1. Using this idea (which was based on a very inappropriate Abbot & Costello routine from long ago)

Three different "EZ-CUT" and paste activities with fractions, decimals and percents. Activity 1: Students cut out proper fractions and match them to equivalent terminating and non-terminating decimals. Some decimals are rounded to the nearest thousandth, others use a vinculum or ellipse to show that it repeats. Activity 2: Students cut out proper and improper fractions and match to equivalent decimals, both terminating and non-terminating. Students round off to the nearest thousandth when nec

So, you’re teaching your kids how to add and subtract fractions, and after a couple of those cruddy worksheets, you decide there’s room for your charges to do something that encourages critical thinking: decimal paths! The trick here is to wind your way through the path, adding and subtracting decimals along the way, until you’ve got the highest total possible. To make it even more interesting, you have to make at least 12 connections. Fun, right? Here are some tips on how to use this in your c

I love those "cut n' paste" activities, but I wonder how much time is wasted by students who have to cut out all those little pieces along the lines and then maneuver them into place. What good are these activities if the students spend 20 minutes cutting and only 10 minutes "thinking" about math? In my version of a "fractions to percents" cut n' paste, I've designed the pieces to be cut out with a minimum of cutting, so that your students can focus on actually "doing the math." By placing the

I love those "cut n' paste" activities, but I wonder how much time is wasted by students who have to cut out all those little pieces along the lines and then maneuver them into place. What good are these activities if the students spend 20 minutes cutting and only 10 minutes "thinking" about math? In my version of a "fractions to decimals" cut n' paste, I've designed the pieces to be cut out with a minimum of cutting, so that your students can focus on actually "doing the math." By placing the

A lot of people ask me where I get all the ideas for my materials, which, you’ll have to admit, are rather strange in many ways. When you see math “everywhere” like I do, you’re always thinking about how math “fits in.” I came home from work one day in the mood to make gungjung tteokbokki, and wouldn’t you know, all I had was frozen pork. So I pulled it out of the freezer and stuck it in the microwave on the “defrost” setting (which actually works pretty well.) What I noticed was that I had purc

Your kids need a reason to convert fractions to decimals? Or decimals to fractions? Here's a fun activity to get your kids psyched to do this: on one side of the page there are mixed numbers (whole numbers and fractions) that have to be converted to decimals so that the amount can be entered on the gas pump. There are "easy" examples with common terminating fractions, as well as "harder" examples where the decimal has to be calculated to the nearest 10,000th in order to be rounded off to the nea

Did you ever notice how many different types of paper towels they have for sale in the market? It’s not bad enough that there are like 5 different brands, but within each brand there are different types: printed, quilted, “choose a size,” and let’s not forget single ply versus double ply. When you figure that you’ll probably go through one of these rolls each week (maybe even more, if your family is anything like mine) and then year in year out, it’s going to be a lot of money! So I decided to

This is a collection of 8, count 'em, 8 different "Yogi-isms" that have to do with some mis-statement of a mathematical concept, featuring a writing prompt in the form of a letter to Yogi Berra explaining his mathematical mistake. The statements include: "90% of baseball is mental; the other half is physical." “You have to give 100 percent in the first half of the game. If that isn’t enough, in the second half, you have to give what is left.” When Yogi ordered a pizza, the waitress asked h

My school uses Connected Math for it’s 6th grade math curriculum; it’s pretty bad in many ways, but on the other hand, it is much better than all the other 6th grade math curricula I’ve seen, which are complete and unadulterated junk (I’m looking directly at you, Go Math!!) The 6th grade unit on rates and ratios has some pretty good activities in it, but I think the use of gummy worms is pretty lame, because, well, I am a believer in the separation between crappy food and educational matter

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....)

Howdy peeps, how are you all doing? I think you’re really going to like this activity (it is not a “product,” it is an activity) and if you paid the royal sum of $3.95 for it, you should consider it a bargain: it represents the work of someone who has 30 years of pre-K through college mathematics behind him, so you know it’s good for your kids. This activity is based on the idea that in order to embed concepts you have to develop “rich associations” between them. That is, when the student “se