Even the mathematically averse among us today recognize the basic geometry that Radolph and Ragimbold failed to grasp, for we live in a numerate society, surrounded by countless manifestations of mathematics. Broadly defined as the ability to reason with numbers and other mathematical concepts, numeracy underlies our current information explosion. Its clichés dot popular speech: “do the math,” “crunch the numbers,” “figure the odds.” From birth to death, numbers track our lives institutionally and demographically. Some scorn such customs (think of Mark Twain’s “figures” of “lies, damned lies, and statistics”), but we all acknowledge numeracy as a cultural given, and agree that mathematics fuels the science, technology, and industry of our world.