Isaac Asimov

Fifty Years," I hackneyed, "is a long time."

"Not when you're looking back at them,"

Robbie nodded his head – a small parallelepiped with rounded edges and corners attached to a similar but much larger parallelepiped that served as torso by means of a short, flexible stalk – and obediently faced the tree. A thin, metal film descended over his glowing eyes and from within his body came a steady, resonant ticking

Mathematicians deal with large numbers sometimes, but never in their income.