The rules for binary addition, allowing for the fact that there are just two digits, are similar to those for addition in any other base.
0+0=0
0+1=1
1+0=1
1+1=0 carry 1
1+1+ carry=1 carry 1
Add the following and convert the answers to denary:
a.
| 0011 | 0101 | 0010 | 0111 |
| 0100 | 0011 | 0111 | 0010 |
b.
| 1000 | 0111 | 1100 | 1110 |
| 0110 | 1001 | 1000 | 1000 |
c.
| 00010000 | 00001111 | 00010011 | 00010001 |
| 00011000 | 01000000 | 10000001 | 00111000 |