## Introduction

The figure shows us a parallelepiped with its main dimensions in centimeters.

These dimensions are presented in the form of **decimal notation**, which corresponds to another form of representation of fractional rational numbers.

The representation of fractional numbers had been known for almost 3,000 years, while the decimal form appeared in the 16th century with the French mathematician François Viète.

The use of decimal numbers is much higher than fractional numbers. Note that on computers and calculating machines we use only the decimal form.

Next: Decimal Fractions