Activity Database

Search
Activity Authors
Activity Circles
Click To Sort By
Grade
Audience
  • 1st - 2nd (9)
  • 3rd - 5th (27)
  • 6th - 8th (77)
  • 9th - 12th (81)
  • College Level (69)
  • For Teachers (78)
Topics
Topics
  • Geometry (35)
  • Mathematical Games (24)
  • Mathematical Modeling (10)
  • Number Theory (26)
  • Parity / Invariants (2)
  • Problem Solving / General (36)
  • Probability and Statistics (3)
  • Social Justice Mathematics (1)
  • Algebra / Arithmetic (32)
  • Combinatorics (32)
Supporting Materials
Supporting Materials
  • Facilitator Guides (87)
  • Handouts (31)
  • Lesson Plan (7)
  • Photos & Videos (24)
  • References (31)
  • Virtual Tools (13)
Session Styles
Session Styles
  • Manipulatives (30)
  • Multiple Representations (27)
  • Problem Posing (45)
  • Problem Sets (45)
  • Try a Smaller Problem (40)
  • Work Backwards (20)
  • Integrates Technology (13)
  • Kinesthetic Element (10)
Mathematical Practices
Mathematical Practices
  • MP1 - Make sense of problems and persevere in solving them. (82)
  • MP2 - Reason abstractly and quantitatively. (47)
  • MP3 - Construct viable arguments and critique others' reasoning. (56)
  • MP4 - Model with mathematics. (54)
  • MP5 - Use appropriate tools strategically. (39)
  • MP6 - Attend to precision. (36)
  • MP7 - Look for and make use of structure. (68)
  • MP8 - Look for and express regularity in repeated reasoning. (61)

Liar’s Bingo

By:


From recognizing a pattern to generating terms, to abstracting and making inferences, tasks based on patterns embody the “low-threshold, high-ceiling” trait of good problems. Liar’s Bingo is all about patterns. This session involves recognizing patterns and searching for underlying structure, number theory, numeration, and potentially binary arithmetic. Sometimes, as in the game of Liar’s Bingo, order seems to arise magically from something we first assume to be random or chaotic. In this case, we use the game of Liar’s Bingo to engage participants’ desire to find patterns, and supercharge that desire by demonstrating a magic trick that captivates attention by...

Locked Out: A Breakout Box Session for Your Circle

By:


Escape Rooms and “Bomb Disposal” activities are growing in popularity as a form of team building and entertainment. This session blends the two ideas to create a cooperative math activity where the challenge is to solve math problems whose solutions generate combinations to open a locked box. The math problems can be selected to fit any audience, and the activity appeals to problem solvers of all ages.

Lockers: An Open-and-Shut Case

By:


A classic Math Circle problem! At a large high school, there are 10000 lockers. The lockers are numbered, in order, 1, 2, 3, . . . , 10000, and to start, each locker is closed. There are also 10000 students, also numbered 1, 2, 3, . . . , 10000. The students walk the length of the corridor, opening and closing lockers according to a set of rules. How many lockers remain open? Which lockers? What if the rules were slightly different? Can you manipulate the rules to obtain specific outcomes? This collection of nine locker problems is suitable for...

Match or No Match

By:


In this session, participants will explore the Match-No Match game: two players each draw one chip out of a bag – if the color of the chips match Player 1 wins, if not Player 2 wins. Under what conditions is this a fair game? How do we know? How can we construct a fair game? What variations of this game are possible? Participants will explore these questions to determine how this game connects to other mathematical problems.

Mathematical Games

By:


This session includes 15 games using manipulatives or paper and pencil. The goal is to decide which one of the two players has a winning strategy. To solve a game means to find a winning, or a non-losing, strategy for one of the players. An answer must include a detailed description of such strategy, and you have to explain what the winning player should do so that this player wins regardless of his opponent’s moves.

These games may be presented as a single circle session, or individually in a circle or classroom.

Mathematical Magic for Muggles

By:


Presented are several easy-to-perform feats that suggest supernatural powers such as telepathy, “seeing fingers,” predicting the future, photographic memory, etc. Each trick uses simple mathematical ideas that allow information to flow effortlessly and sneakily, among them simple, efficient “coding” parity and other invariants symmetry probability One can approach these activities in many ways. At first, you may want to figure out HOW to do a trick. Then, you want to know WHY it works. Finally, you should strive to understand REALLY WHY it works: is there a simple theme or principle behind your possibly complex explanation? Look for simple and...

One, Two, Three, Four: Building Numbers with Four Operations

By:


What numbers can you make with 1, 2, 3, and 4, using the operations of addition, subtraction, and multiplication? Work on these problems builds arithmetic fluency and provides opportunities to identify patterns, develop and defend arguments, and create conjectures. This investigation also highlights how thin the boundary is between a fun warm-up activity for fifth graders and deep questions investigated by research mathematicians!

Optimal Locations of Firehouses (Taxi-cab Metric)

By:


This session asks participants to expand their notion of “distance,” using a nontraditional taxicab metric instead of the usual Pythagorean notion. Participants are guided to construct the equivalent of “circles” with this new metric and to look at the intersections of multiple such circles. In particular, two firehouses in Gridtown are a certain distance apart and at specific addresses. What firehouse should serve a given house with a specified address? What areas of town should each firehouse serve? What if there were three firehouses? The focus of the session is on a deeper understanding of the coordinate system and notions...