SamizdatMath

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

There is no cutesy kids or animals in this activity; it focuses on the math without distraction. This is an activity where children practicing using the "count up" and "count down" activity to make change from whole dollar amounts ($1, $2, $3, and in denominations up to $20.) It is designed to replicate the "real life" experience of giving change when the buyer has a non-whole dollar total. It also gives students practice in making change using coins, or combinations of bills and coins. The goa

This is the same as "Squito" Addition Subtraction but the game uses multiplication and division instead. I invented this game quite by accident: it combines Boggle© with numbers but with a twist: you have a choice of numbers, but the goal is to make an equation that is "as true as possible." Instead of taking a set of cards and then swapping them out until you get an actual equation, students move around a set of numbers to optimize their solution. For example, if you have the digits 7, 3, 0, 8

I invented this game quite by accident: it combines Boggle© with numbers but with a twist: you have a choice of numbers, but the goal is to make an equation that is "as true as possible." Instead of taking a set of cards and then swapping them out until you get an actual equation, students move around a set of numbers to optimize their solution. For example, if you have the digits 1, 2, 4, 4, 6 and 9, and are making a 2 digit + 2 digit = 2 digit equation, what's the closest you can get to a "tru

This is a set of activities which develops the idea of odds and how they can be applied to understanding why the lottery is, at best, a sucker's bet. It takes a list of ten different things that can happen, from rolling a set of snake eyes using two dice (1/36) to being born with an extra finger or toe (1/500) to winning an Oscar (1/11,500) to drowning in a bathtub (1/850,000) to becoming president of the US (1/10,000,000) to winning the Mega-Millions or Powerball lotteries (which have slightly

This is a detailed description of a "strategy" game anybody who can count up to 100 can play with their class and win each and every time. The rules will take about 45 seconds to describe, and within 3 minutes you will be able to keep an entire class occupied by the question, 'why does he/she/they keep on winning this game?" If you follow the instructions described in this activity, it should easily keep a class engaged, puzzled and frustrated for at least 45 minutes, usually longer. Your class

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

Okay, phrens, you're teaching your students how to round numbers and this is what you are NOT going to do: "Students, today we're going to learn how round numbers to the nearest hundreds. To round a number to the hundreds, start by placing your finger on the number furthest to the left (places finger on number) and then look over to the right and then sing this song, "If it's less than 4 or smaller, round it down; if it's 5 or greater, then go right up!" (If you'll pardon the pun.) Then give yo

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 formatted to give you a jolt of color without using up all your ink! There are also single page and double page formats to save enough more

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

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 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

Here is an excellent, excellent game that will get your students thinking carefully and deeply about subtraction, no matter what their age is. If they are in 1st or 2nd grade, they can pratice finding pairs of numbers with single digit answers, and if they’re older, they can practice creating problems that are done mentally or by hand, with or without regrouping (it’s not “borrowing,” folks; for the last time, it’s not “borrowing”) up to three by three digits. It also involves a vast amount of e

This activity came about because my students are endlessly interchanging the words “factors,” “multiples,” and “divisors.” Instead of just having them copy the definitions out of some dumb book, I thought it would be better to have them actually use the different terms to solve mystery number problems. So I adapted another set of activities that I developed for my younger students and came up with this! But I have another item on my agenda: one of the things I have always advocated is giving c

I don’t know what you’ve been up during the summer of 2016, but I’ve been busy doing almost nothing related to my profession. I’ve actually been learning new things, including taking up the sport of boxing. My 69 year old trainer, Bob, says I’m a “natural,” by the way, and my jabs are getting pretty good, although my hook still needs some work. One of the things I did do this summer is do the assigned reading from my school, which was a provocative book by Christopher Emdin, called “For white

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