The approximately symbol is used in math to indicate that two expressions are approximately equal to each other. For example, the mathematical constant (Euler’s Number) is approximately equal to the value as written below.
In reality, there are many more digits needed to represent the Euler’s number, but the approximately symbol is used here to represent that the expression to the left of the symbol is approximately equal to the expression on the right of the symbol.
The symbol for approximately equal is a squiggly equals sign. It is used to show that two numbers are roughly equal, but not exactly equal.