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...
One mile is 5280 feet, one foot is 12 inches. One square foot is 144 square inches, one cubic foot is 1728 cubic inches.
1 gallon of water is 8.34 pounds, and 1 cubic foot is 7.48 gallons, so a cubic foot of water weighs 62.38 pounds. If sand is 2.3 times heavier than water, a cubic foot of sand weighs 143.5 pounds.
I am 5 feet 10 inches tall, or 5.83 feet, or 70 inches. I weigh about 220 pounds, or 3520 ounces. If I’m 65% water, I carry about 143 pounds of water, or a little over 16 gallons.
You go from the single dimensional conversion between m and cm being a factor of 100 and 1000 for m and mm, to the 3 dimensional conversion being a factor of 1 million for m and cm or 1 billion for m and mm. It scales up fast.
Also great way to miss the point. And great use of your calculator. The entire thing is that the metric system is not just "arbitrary amounts", it's all designed to fit together easily.
This isn't some intrinsic value. What you're used to makes the most sense. If you were used to measuring people's height in meters, 1.3 meters vs 2 meters would paint just as vivid a picture.