Floating-point arithmetic

Floating-point arithmetic (FP) is arithmetic that represents real numbers approximately, using an integer with a fixed precision, called the significand, scaled by an integer exponent of a fixed base.

In practice, most floating-point systems use base two, though base ten (decimal floating point) is also common.
— Wikipedia

Example of floating-point number:

12.345 = \underbrace{12345}_\text{significand} \times \underbrace{10}_\text{base}\!\!\!\!\!\!^{\overbrace{-3}^\text{exponent}}

Base two floating pointing is used by default and can produce rounding errors.

This code example for example never terminates:

#include <stdio.h>
 
int main() {
    // Write C code here
     for(double d = 0; d != 0.3; d += 0.1)
        printf("%d", d); // never terminates !!!
    return 0;
}

Decimal (base ten) floating-point usable to work with money values. TODO: add note?

References