Binary patterns can represent numbers.
Complete the table to show the result of the 8-bit binary addition.
| 128 | 64 | 32 | 16 | 8 | 4 | 2 | 1 |
|---|---|---|---|---|---|---|---|
| 1 | 0 | 0 | 1 | 0 | 1 | 1 | 0 |
| 0 | 1 | 0 | 1 | 1 | 1 | 0 | 0 |
Mark scheme
Award one mark for each correct nibble in the correct order:
- 1111 (1)
- 0010 (1)
0 marks if the response is not 8-bit binary.
Example answers and how they were marked
Full marks2/2
1111 0010
Why: 150 + 92 = 242, carrying where a column adds to 2: both nibbles are correct (2).
Some marks1/2
1111 0011
Why: A slip in the last bit. The first nibble is correct (1); the second is not.
No marks0/2
1101 1110
Why: Writes 1 in every column with a 1 and never carries. Neither nibble is correct.