I consider myself pretty conversant in metric units. I know that 20 kilograms is 44 pounds (double it and add 10%) and that five kilometers is a little over three miles (I’ve, uh, run a lot of 5Ks).

LOUISVILLE, Ky. — News of COVID-19 vaccines and deployments have taken over the headlines in recent weeks, and various numbers have been thrown at us: the efficacy, how many doses are needed, and ...

If you’ve ever traveled abroad or heard a story about a cold blast or a heat wave hitting another country, you've likely heard the temperature in degrees Celsius. A hot day would be close to 40 ...

Katie has a PhD in maths, specializing in the intersection of dynamical systems and number theory. She reports on topics from maths and history to society and animals. Katie has a PhD in maths, ...