How do i round 299,792,458 into only 3 significant digits?

Adrop of acetone (nail polish remover) has a mass of 35 mg and a density of 0.788 g/cm3. what is its volume in cubic centimeters?

What effect would average population growth have on land usage? a. urban use of land would rise to more than 30 percent of available land. b. industrial use of land would rise to more than 30 percent of available land. c. the percentage of available land used as cropland would stay the same. d. cropland would fall to about 10 percent of available land.

Which of the following is not an assumption that scientists must make about the natural world? a. regularity b. causality c. predictability d. plausibility