Lesson Plan
Illustrative Mathematics

Illustrative Mathematics: G Srt, G Mg How Far Is the Horizon?

For Teachers 9th - 10th Standards
Some friends are at the beach looking out onto the ocean on a clear day and they wonder how far away the horizon is. A second problem asks how far the horizon would be from the top of a mountain. Students must also answer a question...
Lesson Plan
Alabama Learning Exchange

Alex: Arc Lengths and Sector Areas

For Teachers 9th - 10th Standards
Students will work in cooperative groups to discover the relationships between arc length, central angle measure, and circumference. They will also discover the relationship between circle area, central angle measures, and sector area....
Interactive
Calculator Soup

Calculator Soup: Ratio Calculator

For Students 9th - 10th
The ratio calculator performs three types of operations and shows the steps to solve. It simplifies ratios or creates an equivalent ratio when one side of the ratio is empty, solves ratios for the one missing value when comparing ratios...
Unit Plan
Khan Academy

Khan Academy: Ratio Tables

For Students 5th - 7th Standards
Practice filling out tables of equivalent ratios. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.
Interactive
Fun Brain

Fun Brain: Penguin Waiter (Calculating Percents Game)

For Students 5th - 8th
Players must calculate the correct tip to leave their penguin waiter based on a percentage of the cost of their meals.