In his bestseller, Innumeracy: Mathematical Illiteracy and Its Consequences (1988), John Paulos introduced the term “innumeracy” to refer to “an inability to deal comfortably with the fundamental notions of number and chance.” Paulos bemoaned that innumeracy “plagues far too many otherwise knowledgeable citizens.”
Innumeracy causes many people to struggle with their own personal finances. I’ve personally spoken to people who have taken out payday loans (about which I’ve written quite a bit), who cannot tell me what 10% of $100 is. One problem, discussed extensively by Stanislas Dehaene (The Number Sense: How the Mind Creates Mathematics (revised ed. 2011)) is that human animals are naturally rigged to understand zero, one, two, three and four but on our own we cannot precisely identify or work with greater numbers. To do that, we need an incredible human invention, mathematics, which provides us with an intellectual scaffolding for comparing and manipulating larger numbers. Without a solid grasp of mathematics, humans are left only with vague intuitions about the numerical meaning of the world around them.
How can we help those who are mathematically impaired? Money counselors have often recommend that people stop depending so much on credit cards and operate more on cash. This does two things. First, it keeps you from spending more than you have. Second, it allows you to visualize what you are spending. It causes more pain to hand someone several $20 bills than to swipe a credit card, because you are actually seeing significant amount of cabbage leave your wallet.
I thought of this problem of innumeracy as I viewed an excellent new graphic produced by a website called xkcd.com. The concept is simple, but the execution was excellent and designed to illustrate various salient political issues. The result is an highly detailed image that allows you to see the numbers that are affecting our government and our lives. I invite you to take a few moments (or longer) to visualize thousands, millions and billions of dollars.