Audience: 3rd - 5th

Activity Authors
Activity Circles
Click To Sort By
  • 1st - 2nd (9)
  • 3rd - 5th (27)
  • 6th - 8th (77)
  • 9th - 12th (81)
  • College Level (69)
  • For Teachers (78)
  • 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)

Locked Out: A Breakout Box Session for Your Circle


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.

Mathematical Games


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.

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


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!

Piece of Cake; Delectable Fractions and Decimals


While exploring the relationship between fractions and decimals, participants will have the opportunity to practice operations with fractions, notice and explain patterns, review understandings of place value and number sense, and justify their reasoning.

You can get a taste of math research by repeating these two steps: Think about an interesting unsolved problem, and Do Something to try solving it. Now Think about what you notice, and Do Something to explore your results. Repeat.

Pick’s Theorem


Austrian mathematician Georg Pick first stated this theorem in 1899. However it wasn’t brought to broad attention until 1969. In this exploration, participants will use rates of change to aid them in discovering Pick’s famous formula by finding a relationship between the area of the figure, the number of perimeter pegs, and the number of interior pegs.

This session is also suitable for student circles or the classroom.

Primes, Divisibility, and Modular Arithmetic


Number theory is all about adding and multiplying integers: pretty simple stuff, good for elementary school or for PhD mathematicians. Dr. Arnold Ross says of number theory, that the purpose is “to think deeply of simple things.” So let’s do that together.

This session includes multiple problem sets beginning with prime numbers, continuing to divisibility and its rules, and concluding with Modulo (Modular Arithmetic).

Recruiting Change for a Dollar


How many different ways are there to make change for a dollar? As mathematicians we often search for patterns in a problem. However, for this problem, there is no simple, predictable pattern to build to an answer, encouraging participants to reach outside their comfort zones and ponder alternative strategies in order to make progress.

This monetary problem is engaging, and classroom adaptable with multiple entry points.

Game of Criss-Cross


The purpose for having students play the game of Criss-Cross is to motivate them to explain the underlying mathematical reason governing who wins or loses. This exploration should lead the students to form, test, and ultimately prove conjectures about how to win at Criss-Cross. The game illustrates a beautiful application of the Euler characteristic and gives them practice at elementary counting techniques as well.