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

Many, MANY years ago I had a student in a 7th grade math class who was working on some kind of assignment that required solving the problem 25 ÷ 8. He called me over and pointed out that there must be some kind of error in the problem, because 8 does not go into 25. Being the budding klugarsch that I was, I remarked that, in fact, 8 did “go into” 25 (if you mean how many times can you count up by 8s before getting past 25), but that it didn’t do so without leaving a remainder. Which got me thin

To quote Charles Dickens (from The Pickwick Papers) “What fresh misery is this?” This is what happens when you have time on your hands and you’re thinking to yourself, “well, how can I bring bles’sed torment unto my students this week?” Many (many) years ago I had a student in my sixth grade class (you probably had them) who would respond to any “do now” problem with a quick look and the brag “oh, this is so easy!” And then after fumbling his way through 3 or 4 methods, all featuring a lapse of

Here’s the problem with teaching any kind of technique in mathematics: once you have kids practice it, they discard all the other techniques they know, even if the ones they discard are faster, more efficient and more accurate. Such is the case with teaching “stacking” of addition problems. Sure, it’s a great skill to have, but is it always necessary? I say this: based on some statistic I ran, between 70 - 80% of all addition problems with two addends don’t need to be stacked. Yet we act as if

GaOn is a multi-digit addition/subtraction strategy game that can be played in different ways. Players take turns selecting cards and attempt to form an equation that satisfies the conditions written on the challenge card. Includes game boards, challenge cards, recording sheets and detailed instructions. SamizdatMath does not use or endorse the use of "cutesy" clip art.

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

Teach your students the importance of ratios and unit rates.

This is a game that helps students practice factoring numbers into pairs. The setup is easy: 6 "fish" are taken from the deck and put between the two (or more) players. Each student takes 6 digit cards from the pile (the 0s, 1s and 2s should be removed if playing the "regular" game.) Students "catch" a fish by using two factors from their hand that make that number. For example, if you want to catch the fish labeled "24," you'll need the 3 and 8 or 4 and 6 card. Students take turns removing fish

This is in a similar format to Beginner Division with Remainder Mystery Booklets, but the problems are trickier because they use larger numbers. This is a collection of 10 different "Carrot Power" four-step problem booklets. Just cut and assemble with a single staple, use over and over again because students answer the questions on a separate answer sheet. Each problem uses different clues, 2 - 3 of which have to do with division and remainders. For example, one of the clues would be "when the

This is a collection of 10 different "Carrot Power" four-step problem booklets. Just cut and assemble with a single staple, use over and over again because students answer the questions on a separate answer sheet. Each problem uses different clues, 2 - 3 of which have to do with division and remainders. For example, one of the clues would be "when the number is divided by 3, the remainder is 2." Students answer each clue independently, which together narrow down to a single solution. These are

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

No, it's not a "scoot" game or a tradition "bingo" game; this is an estimation strategy game where students use 4 numbers to create a fraction and then turn it into a decimal (either by hand or using a mental strategy, NOT LONG DIVISION!), round it off (if needed) and then find a square that satisfies that decimal. However, there are many ways to choose a square: some clues are "between" clues ("between .2 and .3") or "exact" clues ("exactly .25") or "less than" clues ("less than .2") which mea

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%