What is pi anyway?  After this set of activities, your pupils should have multiple answers to this question. Investigate pi with various experiments and discoveries. Calculate the ratio circumference/diameter for different sized...

Seamounts are large, extinct volcanoes that rise up from the bottom of the ocean floor. They are a relatively new landform in the scientific community, and this lesson invites students to learn about the amazing diversity of life found...

Students explore different size circles to discover the relationship between diameter and circumference. In this circles and Pi lesson plan, students construct simple parachutes using circle patterns of varying sizes. Students predict...

Students work with circles, angles and estimating angles in the night sky. For this circles and angles lesson, students practice measuring a degree using the circumference of a circle and apply the degree to determine a way to use their...

Students examine the relationship between circumference and diameter and how to use the formula to find the area of a circle.  For this circle lesson students divide into groups and complete an activity. 

Students examine how the circumference, diameter, and the relationship of Pi of a circle are related. They count the summer rings of a tree to determine its growth.

Students examine structural features.  In this life science activity students complete an activity and quantify the impact of various modifications. 

Middle schoolers work with scientific notation and rounding as they determine volume. In this volume lesson, pupils attempt to calculate the volume of the planet Jupiter. They use rounding to two significant digits and scientific...

Students describe the importance of structural features that increase surface area in a coral reef habitat.  In this investigative lesson students quantify the impact of modifications on surface area in model habitats. 

In this symbols worksheet, students read about how different symbols are used to represent variables or constants in equations. Then students complete 3 problems.

Several good activities here. Look particularly at Wheel Figure It Out (which is the opening page) and Gearing Up. There are answers to the very good questions at the bottom of each.