The area of a room is 20 square meters, paved with 1 meter long, 1 decimeter wide, 2 cm thick wood floor, at least () cubic meters of wood floor

The area of a room is 20 square meters, paved with 1 meter long, 1 decimeter wide, 2 cm thick wood floor, at least () cubic meters of wood floor

If it's a math problem, it's like this:
20 * 0.02 = 0.4m3

The density of rice is about that

Measuring weight: 1 use the tray balance to weigh n grains of rice as m, then the average weight of a grain of rice is m / N. 2 borrow a plastic bag with negligible weight to load n grains of rice, and the weight measured is g (gravity value), then the average weight is g / n. measuring density: use the measuring cylinder to measure a ml of oil (water is not recommended, because rice will absorb water)

What is loose density? Is there a difference between bulk density and bulk density

The bulk density includes the average density of the bulk of loose particles in the inner and outer pores of particles and the voids between particles. It is calculated by dividing the total mass of non compacted particles in the state of natural accumulation by the total volume of the bulk materials