Curated OER
Looking into Eratosthenes' Radius of the Earth
Pupils, in small groups, research Eratosthenes and his calculations of the Earth's radius. They write a summary of the person, the experiments and his calculations to determine how accurate Eratosthenes was in his estimations of the size...
Texas Instruments
Circle Equations
Students explore the coordinate plane. In this secondary mathematics lesson, students follow a set of directions to plot points in the coordinate plane.