What’s In My Brain: H vs Arrow

Two columns. One is an example, one isn’t. Can you figure out the hidden rule before the big reveal?

Crossing Every Bridge Exactly Once (aka Eulerian Paths)

How can you cross each bridge in this city exactly once?

Math Curiosity: Magic Triangles

Can you make each side of this triangle add up to 9 using the digits 1-6?

How Many Will There Be? Chip Off The Block

Give kids a taste of a sequence, let them build an understanding, and then see how far their predictions can take them.

How Many Will There Be? Earthworm

Give kids a taste of a sequence, let them build an understanding, and then see how far their predictions can take them.

How Many Will There Be? Courtyard

Give kids a taste of a sequence, let them build an understanding, and then see how far their predictions can take them.

How Many Will There Be? Checkerboard

Give kids a taste of a sequence, let them build an understanding, and then see how far their predictions can take them.

How Many Will There Be? Crosses

Give kids a taste of a sequence, let them build an understanding, and then see how far their predictions can take them.

How Many Will There Be? Squares in Squares

Give kids a taste of a sequence, let them build an understanding, and then see how far their predictions can take them.

How Many Will There Be? Pyramids

Give kids a taste of a sequence, let them build an understanding, and then see how far their predictions can take them.

How Many Will There Be? Sliced Circles

Give kids a taste of a sequence, let them build an understanding, and then see how far their predictions can take them.

How Many Will There Be? Xs and Os

Give kids a taste of a sequence, let them build an understanding, and then see how far their predictions can take them.

How Many Will There Be? Desks

Give kids a taste of a sequence, let them build an understanding, and then see how far their predictions can take them.

How Many Will There Be? Stairs

Give kids a taste of a sequence, let them build an understanding, and then see how far their predictions can take them.

How Many Will There Be? Flowers

These flowers sure are getting bigger faster! How large will they be in step 10? What about step 50?

How Many Will There Be? Triangles Within Triangles

A triangle splits and splits and splits again. How many will there be in step 20?

Math Curiosity: Klauber’s Triangle

In 1932, a leading authority on rattlesnakes, Laurence Klauber, discovered a startling pattern within a triangle of primes.

Math Curiosity: Ulam Spiral

What if we make a huge spiral of numbers and then highlight only the primes? Well, a bunch of weird patterns show up!

Math Curiosity: A Pattern Packed Triangle

Pascal’s pattern-packed triangle is a potent puzzle for pupils to ponder.

What’s In My Brain: Trapezoids or Not?

Which are trapezoids and which are not?

Math Curiosity: The Coloring Problem

No video gets me more email from students! How few colors can you use to color in any map so that no two, neighboring regions are the same color?

Math Curiosity: Odds & Squares

Why does the sum of the first 5 odds also equal 5 squared?

Math Curiosity: Primes and Squares

Can any perfect square be written as the sum of two primes?

Math Curiosity: Legendre’s Conjecture

It seems like there’s always a prime number between two perfect squares… but is this always the case!?

Math Curiosity: Twin Primes

What do you call two prime numbers who are very close together?

Math Curiosity: Palindromic Number Conjecture

Using this one weird trick, it seems that you can turn any number into a palindrome!

Math Curiosity: Collatz Conjecture

The Collatz Conjecture: start with any number and get to 1 using just two rules. It seems to always work…