SamizdatMath

FACT: Students need more practice solving subtraction problems. FACT: This collection has lots of subtraction problems. FACT: Not all subtraction problems are the same: some are "take away," some are "let's compare one with another," some are "I have something and took away this, now I have this...." This is a collection of over 200 different "Busy Bee Hive" puzzles where students practice subtraction in a context that is fun and thoughtful. That is, yes, they get lots of opportunities to do "ta

BY SPECIAL REQUEST! For those of you who enjoyed Coin KenKen and Ultra Coin KenKen, I know bring you TURBO COIN KENKEN: a 5 x 5 grid with half dollars, quarter dollars, dimes, nickels and pennies to arrange on a grid so that the values equal to the shaded in area, and all coins appear once in each column and row. 5 puzzles, 5 answer sheets. Happy Problem Solving to All!

This is NOT your typical "is this a prime or composite number, and if it is composite, show the prime factor" exercise. No, this is an activity that actually demonstrates how figuring out prime factors is linked to encrypting information securely. If you know about the Russian Postal Service puzzle, then you'll appreciate this. There are 10 different puzzles, and then a "DIY" where your students can make their own "prime puzzlers" to share with one another. If they're really good, send them to

Okay, you're teaching your kids how to do two and three column addition.... WHAT A SNOOZE! I promise you, this is going to be fun! Here's how it works: you've taught your students about regrouping/carrying in multi-column addition, and they've done a few problems and you want them to have a little more experience with it while doing some deep thinking. This is the activity for you! This collection of "ink blot addition puzzles" will engage your students in a completely different way, because

This is the one and only collection of "MadHard" 'puzzlas' that I have been collecting, editing and finally, answering for more than a decade. Each one is designed to test the mathematical meddle of your kids, from 3rd through 8th grade. Are they hard? Oh, some are sooooo hard that they even stumped mathematicians! Others are a little less hard, but they're all pretty unique and fun and the contexts are nothing like you've ever seen before. Here are some examples: • A cute baby dressed as a tac

The concept is simple: add two adjacent hexagons to find the sum and fill in the hexagon ABOVE them, and subtract two adjacent hexagons to fill in the difference in the hexagon BELOW them! Sounds easy, right? Well, maybe not: it's not like you can just start in the middle row and move up and down: to solve it, you have to locate the right place to start, which may be a row up or down, or near the top or bottom. As you fill in each of the solutions, more and more clues emerge, and eventually th

Think about it: the average American eats over 40 slices of pizza a year; if you live to be 80, and assuming you start at around 5 years old, this is 75 years of pizza x 40 slices per year, or 3,000 slices in your lifetime! Since this delicious food is such an important part of our life, doesn't it make sense that we understand everything there is about the economics of buying pizza? This is a series of activities that examines the economics of pizza in several different ways. First, it shows

This is the same as Number Logic Puzzles Silly Creatures with a Christmas holiday theme, which should really motivate your students! This is a fun little booklet that your students can put together in about 3 minutes and we’ll really give them some fun 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. Ain’t that cool? Comes in b//w and color booklets - the color booklets have been for

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

"On a bad day, I have no ideas. On a good day, I have a lot of wrong ideas. At least with wrong ideas, I can mix them together and come up with a right answer." That's the idea behind this number puzzle, which I've intentionally designed to be really tricky and frustrating (at least, it was for the 3rd through 6th graders I tried it on.) The relationship between the three columns appear to be arbitrary, but there actually is some method to the madness: the students should be encouraged to come

This is a "bingo" style game where players have to get 5 in a row. Sound pretty boring, right? Well, it ain't. Here's why: instead of just being a "one to one" correspondence game where the teacher calls out some bogus fraction (like, uh, 4/5 = ? %), this is a game where students choose from 4 numbers, create a fraction and then convert that into a percent, and then choose whatever square fulfills that percentage. Except the squares are not all exact percentages: most of them are "between 20%

This is a collection of 10 different algebra puzzles that use 3 different variables which are represented as rectangles, triangles and hexagons. Yes, we know that "adult" algebra uses X, Y and Z, but since this is designed to be appealing for our younger students (and because abstraction is still tough for them) I've used these geometric shapes instead. I've also limited the kinds of numbers students use by focusing on using 0 - 9 digit cards. This is so your students will not get frustrated wh

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

Here’s something that I tried out on my 3rd through 6th graders and which was pretty successful: the idea was to have my students practice division facts, while making sure that they got practice in multiple formats. So this game is kind of a “twofer” - practice the facts AND practice different formats at the same time! Actually, it’s more like a “6-fer” because there are 5 different division formats: two of them use the steifel (the division house) using both a missing quotient but also a mis

This is a short activity with specific instructions that deals with the misconception that the decimal point is the "center" of the base ten system. The reality is that the decimal point has two functions, one of which is to act as a "pointer" to the ones place, which is the actual divider of the place value chart. This goes a long way towards explaining to your students why there is no "opposite" of the ones place: it is the actual center from which the decimals and whole numbers originate. Th

This is a collection of 10 different division word problems that are intended to be sorting into one of three different categories. To learn about these categories (as well as buy this activity for the same price), you can watch my incredibly informative and entertaining video Division: You Really Don't Know What It Is.... This comes complete with sorting mat, teaching instructions, solutions and extension.

This is a fun approach to understanding the importance of ratios and proportions when working with visual arts: I took the famous Gilbert Stuart photo and cropped it so that it would be 2" x 3" and then made enlargements based on adding 1" to both the width and the height. The result is a distorted George that looks like he has had a tooth removed; Seriously, the idea here is that your students look at a series of photos, measure them in inches, and then organize that information into a chart w

Did I ever tell you that I design amazing assessments? Everybody says so: they are the best assessments you've ever seen. The other assessments you've seen? They're a disaster. Sad. This is a percent assessment that is unlike any that you have ever done. First, it requires your students to use scissors! Second, there are very few "clean" numbers (that is, exact numbers) because, well, life is NEVER exact! Third, it assesses on concepts and skill AND problem solving, so your students have to in

Note: There is now a video tutorial that goes with this activity: Division With Remainders: Just Do It (RIGHT!) Your students are "learning" about division, and if you're using a really, really cruddy curriculum, then they probably all sound like this: "I have 24 blah blah blahs which I'm packing into cases of (choose some divisor of 24.) How many cases will I be able to make. This, my friends, is a lackadaisical and churlish approach to teaching students about solving problems with division.

This is a wonderful addition puzzle that somebody showed me: apparently, it was invented in 1916 by the German mathematician Issai Schur and it looks like this: suppose you were to put a set of numbers into two partitions so that no two numbers added up to a third number in that partition? How high could you get, if you started with 1? In this case, you have 2 "cauldrons" and you put 1 in the first cauldron, 2 in the second, 3 in the first, but you have to put 4 in the second, because 1 + 3 = 4