Figuring Out The Numerical Value for Each Arrangement of Bits

Bits Used What Number is This? Answer
1 Bit 0 0
1 1
2 Bits 10 2
11 3
3 Bits 100 4
101 5
110 6
111 7
4 Bits 1000 8
1001 9
1010 10
1011 11
1100 12
1101 13
1110 14
1111 15
5 Bits 10000 16
10001 17
10010 18