SamizdatMath

This is an activity that teaches students to classify acute, obtuse, straight and right angles using semaphore flag signals. Why semaphore flag signals? Because they're fun, interesting and "real." And also, they're a good example of how to teach a concept beyond the "prototypes." What do I mean by this? Well, do an image search on "right angle" and you'll see that the examples that show up are "textbook prototypes." That is, they all have a side resting on the horizontal, the other on the verti

Here’s a nice little “take home” activity that develops both visual spatial skills, mathematical vocabulary AND it's really fun! Here’s how it works: print out the puzzles and challenge booklet on card stock (or laminate before cutting out...) and have your kids cut them out. The kids cut out the “clue cards” and have kids write clues about the different puzzles. Then they can share their cards and look at one another’s clue cards, find the shape it is describing and use the puzzle pieces to “s

This is an investigation where your students design, cut out and fold different networks in order to determine which ones will become a cube. Students are introduced to the concept of a network, learn how it can be used to form different types of polyhedra, and then investigate different ways (there are 11) to create a 2-D net that can be folded into a cube. Students then take the "working" and "non-working" nets and sort them onto a sheet, then compare their properties. There is also an activi

This is a short (40 minute or less) computer based geometry activity which gets students thinking about polygons "outside the box." In this case, it is looking at how to create a closed polygon by adjusting the angle with the number of sides. The activity uses "Papert," an online version of the LOGO computer language that can be accessed at the website http://logo.twentygototen.org. This activity describes in detail to small amounts of code needed to unlock the mystery of the "Total Turtle Trip

It's a simple diagram with a lot of different triangles of lots of different sizes and lots of different directions. There's equilateral, isosceles and scalene, and there are obtuse, acute and right triangles. This activity shows how you can use this diagram to motivate your students to "see" triangles regardless of shape and orientation. Includes detailed suggestions on how to use in your class, as well as an answer key with not 1, not 2, but 3, count 'em, 3 different ways to count and keep tr

What are your students going to make their dads for Fathers Day? Yet another pen holder or a photo mouse pad? I'm a father, and I can guarantee you that those won't fly. Why not make dad a puzzle that he can patchka around with for a few months or years? This is a "threefer" activity: it gets your kids to work on solving geometry puzzles, which they then make into a Fathers Day gift for that special father in their life, AND it is a "clue game" where kids classify shapes according to their att

Greetings 3-D fans: this is a second edition of puzzles designed to be used with Snap Cubes or Multi-Link Cubes (NOT Unifix Cubes, unless you purchase a separate zero-gravity diode, which is currently out of stock....) We live in an era where children spend the majority of their time at home or in school looking at a screen: they swipe, tap and click their way through lessons or activities, and what do they get out of it? Bubkus! These are puzzles designed to develop and improve your students

This is a cool activity where your students practice their ruler skills, as well as composites of 10, and end up with a mathematical flower card which they can sign and give to their moms to hang on the refrigerator!

15 Geometry Area Challenges for ALL LEARNERS! • Don't you hate the way those practice sheets all show the base and heights of the figures your students are calculating the area? • Don't you hate the fact that the bases are always on the bottom, and the heights are always in the middle? • Don't you wish your students could do something more than "plug & chug" some numbers to get an answer? If these are your issues (at least, in mathematics; I don't do anything else...) then you should definit

Listen close and listen good: the only way your students are going to understand and master an important mathematical skill like finding the area of a trapezoid is by engaging in deep and challenging problem solving explorations. It's true and you know it. So don't be a slouch: try these "one cut" dissection puzzles on your kids - they have to cut out the trapezoids, make a single cut and then reassemble the pieces into a parallelogram (well, actually a rhomboid, but you can read my instruction

This is the ultimate and penultimate guide to teaching the area of a triangle. If you're teaching your students the formula base x height ÷ 2 and handing them a bunch of problems where you show the base and height and have them do the rest, well, you're just wasting your time, and miseducating your students. Smooth move, Ferguson... Here's are three essential things you should be teaching your students about finding the area of a triangle, some or all of which you are not teaching: 1) Every tr

If you're going to teach your students about how to find the area of a parallelogram (actually, it's technically a "rhomboid," because a parallelogram could also be a rectangle....) then you're most likely going to doing something bad like "multiply the base times the height," give a couple of dumb problems and call it a day. That's NO way to teach geometry, more or less math, or anything for that matter! This is a collection of geometric "dissections" where students cut out rhomboids, and, us

Here’s something cool that you can do with your students to help them develop and use the vocabulary of geometry, as well as refine their observation and reasoning skills. It also gets your students to think about what are “good” questions to when classifying a shape, and then how to follow those questions with more questions. The game itself is simple: print up the shape cards, cut them out and tape them onto students’ backs. The students then walk around the room asking “yes/no” questions a

This is an activity that I created for my teacher to do during a weeklong overnight trip, but I thought it would be great to use in the classroom as well. There are 20 different clue cards that ask students to look at a set of 7 geometric shapes and pick out two that can be combined to make a third shape that has specific properties. The students sketch the solution on an answer sheet, and name the shape they created. This activity covers acute, obtuse and right triangles, as well as equilatera

What you’ve just purchased is a very decent alternative to “tangrams” and “pentominoes.” Please allow me to introduce you to the wonderful world of “Van Hiele Tiles.” Actually, these have nothing to do with the great educational theorists Dina van Hiele Geldorf and her husband, Pierre van Hiele (but it does, which you’ll see if you continue reading.) This puzzle originated in Germany with the Anchor Stone Company, which made building blocks and geometric puzzles using an artificial “stone” made

Here’s what I’m throwing down in this activity: many of us are teaching surface area and volume of rectangular prisms, but other than memorizing a set of formulas, our students are not getting a whole lot out of it. Of course, you can blame that obsessive focus we have on standardized testing for our compulsion to teach - test - move on to the next topic, but c’mon, you can do better than that, right? This is a short activity that you can do in one period that will not only help your studen

This activity is an invitation for your students to take part in an original piece of mathematical research. We begin with a problem: there is a 6 x 6 apartment split up into 36 "tiles" that need to be arranged so that all 4 apartments use the same number of tiles (9 each) and where each apartment is the exact same shape. Oh, and the apartment has to include a bathroom and kitchen, as shown on the floor plan. From here, the problem morphs into a larger exploration of how many ways this 6 x 6 ti

In this activity, students build a device that allows them to classify angles as acute, obtuse, right, straight and reflex, and estimate their measures using "landmark angles." The template can be cut out and assembled in about 8 minutes using scissors, glue stick, a hole puncher and a paper fastener. I've included step-by-step photographic instructions on how to cut out and assemble the device. Included in this activity is a set of 12 angle classification and estimation "clue cards" which stu

This packet is my way of serving all masters concerning the implications of summer math work: it has a limited number of activities that are not high stress - in fact, it’s five different games, some classic (Picos, Fermis and Bagels, Salute! & PIG!) and others that will be “new to you” (By the Digits, Close to 100), as well as a geometry puzzle featuring the Sphinx puzzle pieces.  Here’s what you get: • Picos, Fermis and Bagels: This is based on the board game “Mastermind,” which challenges

This is a fun activity I whipped up for my 5th grade teachers: basically, it helps students understand the relationship between surface area and volume of a solid by seeing that it is possible to remove cubes from a solid without affecting its surface area, but that its also possible to re-configure a solid so that its volume remains constant while changing the surface area. What's fun about this activity is that it the answers are "sketches" - that is, the students record their answers in isom