Other handy metric things:

1 liter of pure water masses 1 kilogram.  It also weighs 1 kilogram for all practical purposes.   aka  1 grams of water = 1 cc.

1 kilogram is about 2.2 pounds.
A metric ton is 1000 kgs (~2200 lbs), a us ton is 2000 lbs.

1000 CC = 1 liter

There are ~2.54 CM to an inch.  One Cubic Centimeter is 1 CC.  QED a cubic inch contains 2.54**3 CC's (~16.39), so a 2 liter bottle of Coke has ~122 cubic inches of soda in it.  e.g.  Once you remember the 2.54 CM to an inch number you can convert most distances and volumes and masses.  Remember the 2.2lbs to a kilogram and you have mass/weight under control.

Density is written in terms grams/cc pretty universally - so when you see 2 guys carrying a chest full of gold in a movie, you can pretty quickly call "bullshit".   Say that chest held 2 cubic feet of gold...  that would be 12x12x12x2 cubic inches = 3,456 cubic inches = 56,643 CCs.  Gold is 19.32 times as dense as water (e.g.  19.32 grams/cc) = 1,094,359 grams or 1,094kg, or a bit over 2400 lbs...