2 Decimal Notation in Arithmetic Decimal notation is used in the representation of whole numbers, fractions and irrational numbers. Decimal notation allows us to write down these numbers easily. Further, before decimal notation appeared, addition, multiplication, division and subtraction were complicated operations. People had to use the abacus or Roman numerals or other means for calculating. Imagine, if you can, how to do arithmetic without decimal notation.
Decimal notation is the key to our doing arithmetic easily.
Decimal notation is itself a shorthand notation for the representation of numbers. Since the 16-th century A.D. popularization of decimal notation, rules and methods have been invented or found to say how to write, add, multiply, divide and subtract numbers and fractions with this notation. Today these methods or variants of them are taught in elementary school. 13 Good or understandable shorthand helps people to describe calculations and even to do them. The ease with which we write or record numbers and calculations affect the way in which calculations are done and if they are done.