Starting with two 4-bit 2’s-complement words, we want to add +5 and +7 to obtain the correct answer of +12 with a 5-bit word. Show how an extra bit can be added at the left of each of the 4-bit words...

Starting with two 4-bit 2’s-complement words, we want to add +5 and +7 to obtain the correct answer of +12 with a 5-bit word. Show how an extra bit can be added at the left of each of the 4-bit words such that numbers up to can be represented. This approach is called sign extension and can be used to increase the word size of any number.