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?

What’s In My Brain: Pentagon vs Pentagon

We’re looking at regular vs irregular polygons.

Grouping Shapes by Parallel and Perpendicular Sides

Which shapes go together based on parallel and perpendicular lines?

Letters With Symmetry

Let’s group letters by their symmetry, then create symmetrical words, and then symmetrical sentences!

Math Curiosity: Magic Triangles

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

Geometry Image: Esplanade Theaters

What odd and interesting shapes can your students find in this geometric image?

Geometry Image: University Ave

What odd and interesting shapes can your students find in this geometric image?

Geometry Image: Victoria Conference Center

What odd and interesting shapes can your students find in this geometric image?

Geometry Image: Skytree

What odd and interesting shapes can your students find in this geometric image?

Geometry Image: Steigerwald

What odd and interesting shapes can your students find in this geometric image?

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.

What’s In My Brain: Trapezoids or Not?

Which are trapezoids and which are not?

Same Perimeter, Different Area For Rectangles

Can two rectangles have the same perimeter but… different areas!?

Intersecting Angles and Streets

There can never be just one angle.

The Angles of a Triangle

Why tell a kid the rules of a triangle when they can discover them!?

Grouping Quadrilaterals In A Hierarchy

Can we classify quadrilaterals like we classify living things?

Lines, Line Segments, Rays, and Infinity!

A lesson about lines, line segments, and rays that avoids dull memorization. Instead, we ponder this delightful question: Which is longer, a ray or a line? Then, kids consider what these different geometric concepts would think about each other.

Deducing the Area of Triangles

Using patterns, students try to deduce where that area formula came from.