Collaborative Mathematics

VIDEO CHALLENGES

Each of these 16 problem solving challenges is presented in a short video. Problem solvers are invited to watch the videos, give the problems a try, and create a response video in which they explain their solution.

Ermer Numbers

In which we must count all of the numbers whose digits have a certain pattern.

Multiply & Flip

In which we explore how multiplication causes some numbers to flip themselves.

Finger Counting

In which we learn a new technique for counting on our fingers, then make a prediction.

Two-key Calculator

In which we determine how hard it is to solve certain problems with an underpowered calculator.

International Paper

In which we explore the geometric properties of different sizes of paper.

Pieces of Eight

In which we must accomplish a task given a limited set of mathematical building blocks.

String Theory

In which we undertake a subtle and surprising probability experiment.

Confetti

In which we learn a pair of procedures for ripping up paper, then predict.

Awe of Large Numbers

In which we explore two different applications of huge numbers.

Pandigital Puzzles

In which we use the ten digits to tackle a trio of tricky tasks.

Problem With Pirates

In which we must divide a pile of treasure among a band of greedy pirates.

Parenthesizations

In which we count the different ways to apply a particular piece of punctuation.

Numerical Recycling

In which we explore the workings of a mathematical recycling procedure.

Tick, Tick, Tick...

In which we keep time with a ticking pair of out-of-sync clocks.

Pizza Party!

In which we share some pizza with friends, and learn what we have in common.

Palindrome Multiples

In which we seek numbers that have two different properties at the same time.