The One's Complement method is another way of representing positive and negative numbers. This method consists of taking a binary number and making all the '0's in the numbers '1's and vice versa. The new binary number now represents the negative of the original number. For example, the binary number '01101' represents the decimal number '13'.

Using the 'One's Complement rule, you can find '-13' by inverting the binary number. The inversion of '01101' should end up as '10010'. Therefore, the binary number '10010' in One's Complement is equal to '-13'.

The range of this method is the same as normal binary, however, as it also represents negative numbers, the positive range is halved. For a regular 8 bit binary number, the range from 0 to 256, giving it a range of 256. However, using an 8 bit binary number with the 'one's complement' method, the range is still 256, but is a range from -128 to 128.

The main problem with this method is the fact that it has two ways of representing 0. Both '00000000' and '11111111' represent the decimal number 0. To fix this problem, the Two's Complement method was created.