From Lee Sallows:

“The above three strips of ten numbers have an intriguing property. They record how many times each of the decimal digits (shown at left) occur in the other two strips. Hence the 6 in the left-hand strip identifies the number of 0s in strips B and C, while the 2 in the centre strip counts the number of 3s present in strips A and C. Moreover, the same property holds for every number in all three strips.”

See Reciprocation.

(Thanks, Lee.)