Decimal is a base (or radix) 10 numeral system. Meaning, the system has ten symbols or numerals to represent any quantity. These symbols are called Digits. The Hindu-Arabic numeric system and Chinese counting rods system are the two systems that required no more than ten symbols. Decimal numeral system is the most commonly used numeral system perhaps because humans have ten digits over both hands.

We would look into the Hindu-Arabic system as it is commonly used all around the world. The ten symbols are 1,2,3,4,5,6,7,8,9 and 0. The two great Indian mathematicians could be given credit for developing the Hindu-Arabic system. They are Aryabhatta of Kusumapura who lived during the 5th century developed the place value notation and Brahmagupta a century later introduced the symbol zero. Though the concept of zero has been around for a long time, Indians gave the symbol for zero '0' which is used today.

Many system follow some way to represent the quantities by using finite number of symbols. That some way in this decimal number system is weightage. Each digit in a number is given weightage depending on its position. Eg on how a number is represented in a decimal number system is show below.

As we move towards left from the decimal point, the weight given to the digit increases by a factor of 10. As we towards right from the decimal point, the weight given to the digit decreases by a factor of 10.

So 17.591 can be expanded as 1x10

There are many systems similar to decimal system with different bases. Hence if two or more systems are used simultaneously, to distinguish what numeral system is used to represent a number we use the form something like this 17.591

Since weights are given to the digits in the number, it is one of the positional or place value numeral system.

We would look into the Hindu-Arabic system as it is commonly used all around the world. The ten symbols are 1,2,3,4,5,6,7,8,9 and 0. The two great Indian mathematicians could be given credit for developing the Hindu-Arabic system. They are Aryabhatta of Kusumapura who lived during the 5th century developed the place value notation and Brahmagupta a century later introduced the symbol zero. Though the concept of zero has been around for a long time, Indians gave the symbol for zero '0' which is used today.

Many system follow some way to represent the quantities by using finite number of symbols. That some way in this decimal number system is weightage. Each digit in a number is given weightage depending on its position. Eg on how a number is represented in a decimal number system is show below.

As we move towards left from the decimal point, the weight given to the digit increases by a factor of 10. As we towards right from the decimal point, the weight given to the digit decreases by a factor of 10.

So 17.591 can be expanded as 1x10

^{1}+ 7 x 10^{0}+ 5 x 10^{-1}+ 9 x 10^{-2}+ 1 x 10^{-3}which is equal to 17.591There are many systems similar to decimal system with different bases. Hence if two or more systems are used simultaneously, to distinguish what numeral system is used to represent a number we use the form something like this 17.591

_{10}. This indicates that 17.591 is expressed in base 10.Since weights are given to the digits in the number, it is one of the positional or place value numeral system.