Illuminations: Parts of a Square
Illuminations (National Council of Teachers of Mathematics)

Students investigate the ways shapes can be divided into equal pieces with one or two cuts.

Illuminations: Describing Designs
Illuminations (National Council of Teachers of Mathematics)

Students create designs and describe them to a classmate, using fractional and geometric terms.

Illuminations: Discovering the Area Formula for Triangles
Illuminations (National Council of Teachers of Mathematics)

In this lesson, students develop the area formula for a triangle.

NRICH: Seeing Squares
NRICH (University of Cambridge)

Players take it in turns to choose a dot on the grid. The winner is the first to have four dots that can be joined to form a square.

NRICH (University of Cambridge)

In this problem we are faced with an apparently easy area problem, but it has gone horribly wrong! What happened?

GeoGebra: Surface Area of a Cube IM 6.1.18
GeoGebra

“Surface Area of a Cube” from IM Grade 6 by Open Up Resources and Illustrative Mathematics.

GeoGebra: Squares and Cubes IM 6.1.17
GeoGebra

“Squares and Cubes” from IM Grade 6 by Open Up Resources and Illustrative Mathematics.

GeoGebra: Dilations on a Square Grid IM 8.2.4
GeoGebra

“Dilations on a Square Grid” from IM Grade 8 by Open Up Resources and Illustrative Mathematics.

GeoGebra: The Volume of a Square IM 8.5.20
GeoGebra

“The Volume of a Square” from IM Grade 8 by Open Up Resources and Illustrative Mathematics.

GeoGebra: When Is the Same Size Not the Same Size? IM 8.8.16
GeoGebra

“When Is the Same Size Not the Same Size?” from IM Grade 8 by Open Up Resources and Illustrative Mathematics.

GeoGebra: Finding Distances in the Coordinate Plane IM 8.8.11
GeoGebra

“Finding Distances in the Coordinate Plane” from IM Grade 8 by Open Up Resources and Illustrative Mathematics.

GeoGebra: Edge Lengths and Volumes IM 8.8.12
GeoGebra

“Edge Lengths and Volumes” from IM Grade 8 by Open Up Resources and Illustrative Mathematics.