Wednesday Why

Why do the teeny little tiny LR44 batteries come in a package of three when I only need two for my calculator? What on earth will I do with just one battery now? I don't even know of anything else in the house that uses an LR44, and I've had this calculator for eons, probably 15 years, and this is the first time I've replaced the batteries!!! Ya think I'll even know where to FIND that third battery in another 15 years, ROFL?