1+2=fish. Connect the ends of the one and with the two ends of the 2 and you get a fish shape. we will now label fish as F. 1+2=F 1+2=3 12=F because you can connect the ends of the two digits F=3 3=12 1=4. Substitute 4 in for 1 in the original equation 4+2=F 4+2=6 6=F 6=F=3 6=3 2=1 F-F=0=6-3 3=0 3-4=0-1 -1=-1 -1+2=-1+2 Substitute 1 in for 2 since 2=1 -1+2=-1+1 1=0 Thus 1+1=1+0=2=1 Since 1=0, all numbers must be equal, for adding 1 to a number is the same thing as adding 0.