Click on a 0 and it changes to a 1. Click on a 1 and it changes to a 0. Each change yields a new 12 digit (residue) binary number. Each residue is one "bit" of information. As can be seen by changing all the residues to 1's, with 12 bits we can count from 0 to 4095. Including 0 itself, that's 1+4095 = 4096 = 2^{12} numbers. 
12 bits account for 4096 = 2^{12} responses. And if you have 4096 responses, that's the same as saying you have 12 bits of information. The number of bits of information = 12 = log_{2} 4096. 


