@jameshowell How old are these students?

@jameshowell Recently heard a good aspect:

The difference between a million and a billion is, to a quite close approximation, a billion.

A different trick I like to use for visualization is to make squares and cubes: a million cubic metres is 100 m × 100 m × 100 m.

Water has a density of 1 g/cm³, so 1 m³ is 1 t (metric ton).

Iron has a density of a bit less than 8 g/cm³, so 1 m³ of that is 8 t.

All the used nuclear fuel ever produced worldwide fits a cube of ~ 35 m sides.

@jameshowell @Timo_Micro Honestly love the third answer.