Starting with a common baseball umpire indicator, we consider the zeroing number for two-wheel indicators with states (a, b) and three-wheel indicators with states (a, b, c). Elementary number theory yields formulae for the zeroing number. The solution in the three-wheel case involves a curiously nontrivial minimization problem whose solution determines the chirality of the ordered triple (a, b, c) of pairwise relatively prime numbers. We prove that chirality is in fact an invariant of the unordered triple {a, b, c}. We also show that the chirality of Fibonacci triples alternates between 1 and 2.