How many number system?

Answer 1

In our base ten system of positional notation, we have 10 symbols, and place values defined by a decimal point. Just to the left is the ones place; to the left of it is the tens place, and so forth.

To the right of the decimal point is the tenths place, and to its right is the hundredths.

Ten is the base. But you can have base 8, base 16, base 2 or base any integer. Remember -- the number of symbols you need is equal to the base.

"Decimal" point is particular to base 10. The general term is "radix point."

To the left of the radix point is the place for the base to the zeroth (base0) power. To the left of it is the base1. Next left is base 2 .

Just to the right of the radix point is the place for the base -1. Next right is base -2 , and, and so forth.

Bases 8 and 16 are useful as shorthands for binary. Binary is useful because arithmetic can be done with arrays of two-state devices.