This box shows by binary mode,
how many
switch levers are down!
This thing can
count
up to two !
A
+
B
=
D
E
O
+
O
=
0
0
Zero...
O
+
I
=
0
1
One...
I
+
O
=
0
1
One...
I
+
I
=
1
0
Two!
move on