G for Grand,or MX depending on what its used for.
Improved Answer:
1000 as a Roman numeral is M
The symbol for one thousand grams is "kg" which stands for kilograms.
In Roman Numerals one thousand is written as M.
It is a kilometre, with symbol km.
The name for one thousand meters is a kilometer, and its symbol is "km." This metric unit is commonly used to measure distances, particularly in geography and transportation. One kilometer is equal to 1,000 meters.
It is the number of tens modulo one thousand.
milli or in symbol: m. E.g. mm is millimetre, mA is milliampere.
If it's Roman Numerals then the symbol is M
10^3.
it is "M"
g
1 k
The M represents 1000, the D is 500 and L represents 50. This would convert to MCDLIX in Roman numerals.