Mathalicious: Domino Effect
Mathalicious

In this lesson, students use slope, y-intercept, and linear equations to explore the costs of different-sized pizzas at Domino’s and debate whether the pizza chain should be more transparent in its pricing.

youcubed: Square Mania (9-12)
youcubed (Stanford University)

In this activity students look into a pattern and diagram where their first task is to verify the number of lines and squares.

Real World Math: Exploratory Lessons - Line Patterns
Real World Math

Students will use the Google Earth path tool to connect markings in a geometric pattern of their design. 

Illuminations: Printing Books
Illuminations (National Council of Teachers of Mathematics)

Students explore the relationships among lines, slopes, and y-intercepts in the context of printing their algebra textbooks.

Illuminations: Smokey Bear Takes Algebra
Illuminations (National Council of Teachers of Mathematics)

This lesson introduces students to the many factors that play a role in creating a forest-fire danger rating index.

Illuminations: Traveling Distances
Illuminations (National Council of Teachers of Mathematics)

In this lesson, students interpret the meaning of the slope and y-intercept of the graph of real-life data.

Illuminations: Automobile Mileage - Year vs. Mileage
Illuminations (National Council of Teachers of Mathematics)

In this lesson, students plot data about automobile mileage and interpret the meaning of the slope and y-intercept in the resulting equation for the least squares regression line.

Illuminations: Pedal Power
Illuminations (National Council of Teachers of Mathematics)

In this lesson, students investigate slope as a rate of change.

NRICH: Diamond Collector
NRICH (University of Cambridge)

Try to collect as many diamonds as you can!

NRICH: At Right Angles
NRICH (University of Cambridge)

Can you decide whether two lines are perpendicular or not? Can you do this without drawing them?

NRICH: How Steep Is the Slope?
NRICH (University of Cambridge)

On the grid provided, we can draw lines with different gradients. How many different gradients can you find? Can you arrange them in order of steepness?

NRICH: At Right Angles
NRICH (University of Cambridge)

Can you decide whether two lines are perpendicular or not? Can you do this without drawing them?Can you decide whether two lines are perpendicular or not? Can you do this without drawing them?