One kilometer is 1000 meters, one meter is 1000 millimeters. One square meter is 1,000,000 millimeters, one cubic meter is 1000 liters.
1 liter of water is 1 kilograms, so 1 cubic meter is 1000 kilograms. Sand is about 2.3 times heavier than water, so 1 cubic meter of sand is 2300 kilograms, or 2.3 metric tonnes.
I’m 1.96 meters tall, or 1 meter and 960 millimeters, or 1 meter and 96 centimeters. I weigh about 85 kilos, or 85.000 grams. Being 65% water, I carry about 55.25 kilograms of water, which will fill a little over 55 one liter water bottles
I can do this all day
Now let’s do the same with imperial units! You first, cuz I’m not going to touch that shit with a 10 foot pole…