Q. Why we need number systems?
Number system is used to signify information in quantitative form. Some of the general number systems are octal, decimal, hexadecimal and binary. A number system of base (also known as radix) r is a system which has r different symbols for r digits. A string of these symbolic digits signifies a number.
To conclude the value that a number signifies we multiply number by its place value which is an integer power of r depending on place it is located and then find sum of weighted digits.