Any binary number can be converted into its equivalent decimal number using the weights assigned to each bit position.
Lets see how to convert binary number (10111)2 to its equivalent decimal number.
1x24 + 0x23 + 1x22 + 1x21 + 1x20
16 + 0 + 4 + 2 + 1
(23)10
As shown above small subscript at the end of the number may be added signifying the number system. For example, (1000)2 represents a binary number and is not one thousand.
Lets take one more example and convert (110101)2 to its decimal equivalent.
1x25 + 1x24 + 0x23 + 1x22 + 0x21 + 1x20
32 + 16 + 0 + 4 + 0 + 1
(53)10