A degree in Spanish got me my first job as a journalist, with an international press agency in Mexico City, but it didn’t prevent me blundering badly as a rookie reporter. I had just arrived in the Mexican capital after a Greyhound bus journey all the way from New York and the job interview was a test of my language skills. In my new role, day shifts were spent on the streets in political rallies and nights were spent alone in the office, coordinating the coverage from strife- torn El Salvador, Nicaragua, Guatemala and the rest of Central America. But, I also had to report on occasional disasters: fires, floods and explosions at fi rework factories. It was as a reporter that I soon found out that I was as bad at understanding numbers in Spanish as I was at calculating them in English. Phone calls meant for the police got Mexican grandmothers out of bed at 2am because I had misunderstood a number and dialled a dodgy digit. Even worse, victims were piled too high in my stories – almost 83 dead in a fi re at 6pm turned out to be as few as 38 by 7pm; 12 people injured in a coach crash soon became two and so it went on. Finally, I got a call from the main office in Washington. “I don’t know what training you have had,” an editor yelled, “but has no one ever told you a death toll can’t go down?!” Why are numbers in another language such a conundrum? It