Why do we use a grand and K to denote a thousand? 

You ask your dad to give you a grand for shopping and he instantly takes out two 500-rupee notes from his purse and hands them over to you. You wear a nice shirt to a party where your friend asks you how much it cost you, and you say 2K. Grand and K have become the frequently-used terms for denoting thousand in the modern day. But you must be thinking that thousand starts with the letter T, so why not use T instead of grand or K? Let’s find out. 

K and its Greek origin  
Greeks used the word ‘khilioi’ to signify “plural of uncertain affinity”. This was abbreviated to ‘kilo’ by the French. Then came the metric system, which introduced kilo as a unit of 1000. Soon after, new terms such as kilolitre, kilogram, kilotonne, etc. were coined to refer to thousand litres, thousand grams and so on. Subsequently, K became short for kilo. And therefore, in essence, one might use ‘10K’ to mean 10,000.  

Inception of the term Grand 
The term “grand” has been in use as an American slang from the early 1900s, presumably from the phrase “a grand sum of money” which meant $1,000. Well, it is not yet clear who first used the phrase. The best we can do, in most cases, is to find the earliest written usage, which is around 1915 for ‘grand’. That said, the term was probably in conversational use for a while before it appeared in writing.  

Within a few decades, the term was so popular that it was abbreviated to G or G-note. During World War II, the Yanks brought the term to the UK, where it came to mean £1,000. By the late 1940s, a grand meant a thousand of almost anything, not just money.  

What’s the point? 
Of course, using these terms has made life a little easier. They save space and takes less time. Another advantage is that you don’t really need to see how many “0s” you are putting behind the number and in the same way it is very quickly understood by the reader or the listener what number is being conveyed. 

More number facts  

• Like ‘grand’, each ‘big one’ means $1,000. So, if you’re buying a laptop for 1 big one, you’re paying a $1000. 
• C is equal to 100 in the Roman numeral system. It stands for the Latin word ‘centum’, which means “a hundred” (‘cent’ also originated from this word). Therefore, a C note is a $100 bill. 
• Do you know it is actually the letter ‘M’ that represents 1000 in Roman numerals? Therefore, Romans use ‘MM’ to mean a million.