Algebraic fraction is an expression of a shape A / B, where A and B can be a number, a monomial, a polynomial. As in arithmetic, A is called a numerator, B – a denominator. Arithmetical fraction is a particular case of an algebraic one. To add or to subtract two or some fractions it is necessary to make the same operations as in arithmetic. Multiplication and division of algebraic fractions doesn’t differ from the same operations in arithmetic. Canceling a fraction can be done both before and after multiplication of numerators and denominators.