RANDOM ACTS OF MATHEMATICAL DELIGHT

Use these teacher-recommended mathematical gems at random moments in your classroom.

Here’s a collection of videos recommended by colleagues across the globe.

Some pieces are short and make for excellent classroom starters. Some are longer for the odd ten- or fifteen- moments of class time. Some are longer still for full class activity.

Have something to share?

Today's Featured Video

Today's Featured Video

Do you know your personal polynomial?

Do you want to see a mathematical formula spells your name? Do you want to see a graph of your formula?

Check out this cool app that shows you your name in math!

Today's Featured Video

Arithmetic

Featured VideoPlay Video

Russian Multiplication from NumberPhile

MIDDLE AND HIGH SCHOOL: Powers of Two: Multiplication done in a fun way using the powers of two.

Featured VideoPlay Video

How High can you Count on Your Fingers?

ALL AGES: Number Sense: The answer to the questions might surprise you!

Featured VideoPlay Video

Baron Hannsz' easy Long Multiplication in Any Base!

HIGH SCHOOL: Polynomials: Let's combine Polynomials, Exploding Dots, and the Area Model for some multiplication magic!

Featured VideoPlay Video

A Square Root of Two cartoon from BEN ORLIN (introduced by James).

MIDDLE and HIGH SCHOOL: Irrational Numbers: The inimitable Ben Orlin selected this gem of a cartoon to share.

Featured VideoPlay Video

Frogs and Buns

MIDDLE SCHOOL: Fractions: What’s a good way to share buns?

Featured VideoPlay Video

Dots & Tods from GMP; Piles & Holes from MINDSETS

MIDDLE SCHOOL: Negative Numbers: Go from this teaser to the full experience: www.mindsets.com/global-math-project

Featured VideoPlay Video

The Golden Ratio

HIGH SCHOOL: Irrational Numbers: Why is the Golden Ratio so irrational?

Featured VideoPlay Video

A Pythagorean Number Puzzle

MIDDLE and HIGH SCHOOL: Order of Operations: A curious puzzle that unites Pythagorean triangles with a numbers game.

Featured VideoPlay Video

A Crazy 6s Puzzle

MIDDLE and HIGH SCHOOL: Geometry of Numbers: There is too much structure here to be coincidence!

Featured VideoPlay Video

How to Multiply Without Multiplying

MIDDLE and HIGH SCHOOL: Powers of Two: A ancient way to compute products

Featured VideoPlay Video

Line Multiplication

GRADE and MIDDLE SCHOOL: Long Multiplication: Can you figure out why this curious method works?

Featured VideoPlay Video

Powers of Ten

GRADE and MIDDLE SCHOOL: Powers of Ten: A classic video giving an intuitive sense of scale.

Pi

Featured VideoPlay Video

Calculating Pi with Real Pies

ALL AGES: Pi: Matt Parker selects this video for us to share (created in collaboration with Brady Haran).

Featured VideoPlay Video

Pi for a Square

MIDDLE and HIGH SCHOOL: Geometry: An old video but a goodie!

Featured VideoPlay Video

A Mile of Pi

ALL AGES: Pi: Brady Haran, the brilliant master of @numberphile, selects this video of Matt Parker's to share.

Equations and Algebra

Featured VideoPlay Video

The Citardauq Formula

HIGH SCHOOL: Quadratics: A strange way to solve quadratic equations

Featured VideoPlay Video

Lill’s Method

HIGH SCHOOL: Polynomial Equations: Solving Polynomial Equations by Shooting Turtles with Lasers

Featured VideoPlay Video

Find your PERSONAL POLYNOMIAL

HIGH SCHOOL; Polynomials and Data: Here’s how to find a polynomial formula that fits any data set

Featured VideoPlay Video

Completing the Square

HIGH SCHOOL: Quadratics: Eddie Woo, winner of Australia’s Local Hero Award, tells us about Completing the Square.

Featured VideoPlay Video

Factoring Simple Trinomials using Algebra Tiles

MIDDLE and HIGH SCHOOL: Factoring: A visual approach to Factoring Trinomials.

Geometry

Featured VideoPlay Video

Infinite Cake Anyone?

MIDDLE and HIGH SCHOOL: Do we understand "area"? How is it that I seem to be generating infinite amounts of cake?

Featured VideoPlay Video

A Cute Paper Trick

ALL AGES: Spatial Reasoning: Can you figure out what is going on?

Featured VideoPlay Video

Why Does Slicing a Cone Give an Ellipse?

HIGH SCHOOL: Conic Sections: Grant Sanderson (3Blue1Brown) shares this lovely video for GMP

Featured VideoPlay Video

Unexpected Shapes

ALL AGES: Spatial Reasoning: Playing with Moebius bands... and beyond!

Featured VideoPlay Video

Alles is Wiskunde!

ALL AGES: Spatial Reasoning: Playing with modular origami.

Featured VideoPlay Video

Reflected Cats - NumberPhile

ALL AGES: Geometry: Tadashi Tokieda plays with the curious geometry of reflections.

Probability and Expected Values

Featured VideoPlay Video

A Gender Balance Puzzle

HIGH SCHOOL: Probability: Here's a puzzle alleged to be an interview question at high-tech companies.

Featured VideoPlay Video

The Surprising Math of Twinkle Twinkle Little Star

ALL AGES: Counting and/or Probability: A curious word-counting phenomenon

Featured VideoPlay Video

What is the Best Way to Win at Monopoly?

MIDDLE and HIGH SCHOOL: Probability: Tom Rocks Maths selects this lovely video for us to share.

Math Salute

Featured VideoPlay Video

The International Math Salute

ALL AGES: Problem Solving: James Tanton teaches James Grime the salute

Featured VideoPlay Video

The Salute in Tanzania

ALL AGES: Problem Solving: Experience exuberant joy!

Featured VideoPlay Video

The Salute Explained

ALL AGES: Problem Solving: James gives away the details

Riddles

Featured VideoPlay Video

The Cuddle Duddly Fuddly Wuddly Riddle

MIDDLE and HIGH SCHOOL: Puzzle: Stop the video before the puzzle is solved

Featured VideoPlay Video

The Giant Cat Army Riddle

MIDDLE and HIGH SCHOOL: Puzzle: Stop the video before the puzzle is solved

Featured VideoPlay Video

The Unstoppable Blob Riddle

MIDDLE and HIGH SCHOOL: Puzzle: Stop the video before the puzzle is solved

Featured VideoPlay Video

The Wizard Standoff Riddle

MIDDLE and HIGH SCHOOL: Puzzle: Stop the video before the puzzle is solved

Featured VideoPlay Video

The Time Travel Riddle

MIDDLE and HIGH SCHOOL: Puzzle: Stop the video before the puzzle is solved

Featured VideoPlay Video

The Rogue AI Riddle

MIDDLE and HIGH SCHOOL: Puzzle: Stop the video before the puzzle is solved

Featured VideoPlay Video

The Penniless Pilgrim Riddle

MIDDLE and HIGH SCHOOL: Puzzle: Stop the video before the puzzle is solved

Featured VideoPlay Video

The Vampire Hunter Riddle

MIDDLE and HIGH SCHOOL: Puzzle: Stop the video before the puzzle is solved

Miscellaneous

Featured VideoPlay Video

How to Split Things into Thirds

MIDDLE and HIGH-SCHOOL Fractions: From folding to sharing

Featured VideoPlay Video

Hexaflexagons

ALL AGES: Spatial Reasoning: The incredible Vi Hart selected this video from among her many wonderful offerings.

Featured VideoPlay Video

Using Video Games to Improve Math Scores

EDUCATORS: GMP Co-Founder Dr Raj Shah gives some profound insights on math teaching in his latest TedEx piece.