Take some time and think about the resources you have available in your classroom. Formulas, diagrams, and conversion information are pretty common.
But what else is available?
Are your students constructing their own length measuring tools?
Or their own volume measuring devices?
Could you hold a Catapult or an Archery Competition?
Might your students build treasure maps?
Or their own sinusoidal graphs using miniature replicas?
Could your students examine the effect of pendulum length on period?
Have they tried some Pythagorean Puzzles?
Or attempted inductive and deductive proofs?
Have your students tried scaling activities?
Would examining the surface area of cones be appropriate?
Or spend time constructing a formula for the area of a circle? A = C/2 x r
Have they built shapes of various volumes?
Have they found experimental values of pi using balloon pumps?
Or compared racing around a circle to racing across a circle?
Could your students graph the surface area and volume of a set of similar pyramids?
Use measurement in your class!
Ground your mathematics explorations in measurements that your students make themselves!