We use B to represent billion, M to represent million, so why do we use K to represent thousand?
It is because of the Greeks and the metric system. There is a Greek word χίλια that means thousand. Antoine Lavoisier, a French nobleman who is known as the father of chemistry, adopted this Greek term in the research he conducted in 1795. Later on, in 1799 during the French Revolution, the French adopted the metric system which was based on the kilogram and the meter. The kilogram got its name from χίλια and was used to measure 1,000.
Long story short, we, in fact, do use the metric system in the U.S– we use K to represent thousand because of the metric kilo.
*Keep in mind that the Greek letter χ is pronounced with a ‘k’ sound in english*
Look up at the stars and not down at your feet. Try to make sense of what you see, and wonder about what makes the universe exist. Be curious.Stephen Hawking