Solve this BCD problem: 0101 + 0110 = ________.

Negation is performed by simply performing the ________ operation.

When performing binary addition using the 2's-complement method, an ________ can occur if ________ are of the same ________; the error is indicated by a(n) ________.

When subtracting 6 from 9 using 2's-complement methods, the ________ is 2's complemented before the addition.

The binary subtraction 1 – 1 = ________.