4 toast, 6 toast

Have you ever tried to order an odd number of slices of toast? Tried to do this a number of times in different hotels but to no avail. One Indian waiter considered this request for several minutes, the mental cogs turning and the furrowed brow contorted, before deciding that "this was impossible". I could have 4 slices or 6 slices, or 8, 10 or 12 for that matter, but not 5. Ok, I will have 6 and leave 1. We ourselves debated this conundrum, and came to the conclusion that the toasters all have 2 slots - riddle solved.