ℚ
Symbol  Format  Data 

ℚ  Code Point 
U+211A 
TeX 
\mathbb{Q} 

SVG 
The ℚ symbols is used in math to represent the set of rational letters. It is the Latin Capital letter Q presented in a doublestruck typeface.
The capital Latin letter Q is used in mathematics to represent the set of rational numbers. Usually, the letter is presented with a "doublestruck" typeface when it is used to represent the set of rational numbers.
Set of natural numbers.
Set of integers symbol.
The set of real numbers symbol is a Latin capital R presented in doublestruck typeface.
The set of complex numbers is represented by the Latin capital letter C. The symbol is often presented with a doublestruck font face just as with other number sets. The set of complex numbers extends the real numbers.