Activity Database

Search
Activity Authors
Activity Circles
Click To Sort By
Grade
Audience
  • 6th - 8th (2)
  • 9th - 12th (2)
  • College Level (2)
  • For Teachers (3)
Topics
Topics
  • Algebra / Arithmetic (1)
  • Combinatorics (1)
  • Geometry (2)
  • Number Theory (1)
  • Problem Solving / General (1)
Supporting Materials
Supporting Materials
  • Facilitator Guides (3)
  • Photos & Videos (2)
  • References (1)
Session Styles
Session Styles
  • Kinesthetic Element (1)
  • Manipulatives (1)
  • Multiple Representations (1)
  • Problem Posing (2)
Mathematical Practices
Mathematical Practices
  • MP1 - Make sense of problems and persevere in solving them. (2)
  • MP2 - Reason abstractly and quantitatively. (1)
  • MP3 - Construct viable arguments and critique others' reasoning. (2)
  • MP5 - Use appropriate tools strategically. (1)
  • MP6 - Attend to precision. (2)
  • MP7 - Look for and make use of structure. (2)
  • MP8 - Look for and express regularity in repeated reasoning. (1)

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...

Probability

By:


Some probability problems can be solved by drawing a picture; this approach is sometimes called geometric probability. Other approaches can include experimentation, looking at smaller cases, looking at extreme cases, recursion, or carefully listing possibilities.

This session includes ten problems that can be explored alone or in sets, providing material for several circle sessions or the classroom.