Measurement has definitley been the hardest unit for me so far. Once provided with a formula sheet, you can figure out lots of different solutions like a recipe. Something I found interesting was how 2 cones fit exactly into a sphere with the same dimensions. This means that a hemisphere is equal to 1 cone. We also found out that 3 cones fit exactly into a cylinder, and 3 pyramids fit exactly into a box of the same dimensions. As shown below.