To find $2\text{'}$s complement of a negative of a number using a $5-$bit pattern. First convert number to binary. If the number of digits is less $5,$ pad with leading zeros, flip the bits $(0$ becomes $1$ and $1$ becomes $0),$ and finally add $1$ using binary arithmetic operation $,$ carry $1$ or $0+1=1.$ Example, write $-10$ in binary using $8-$bit $2\text{'}$s complement.

$10$ in decimal is $1010$ in binary.

pad with zeros to make $8-$bit pattern of $00001010,$

flip bits to get $11110101.$

Add $1$ to get $11110110.(11110101+00000001$