How many people have died because of COVID-19? Which countries have been hit hardest by the virus? What are the benefits and harms of different vaccines? How does COVID-19 compare to the Spanish flu? How have the lockdown measures affected the economy, mental health and crime? This year we have been bombarded by statistics - seven day rolling averages, rates of infection, excess deaths. Never have numbers been more central to our national conversation, and never has it been more important that we think about them clearly. In the media and in their Observer column, Professor Sir David Spiegelhalter and RSS Statistical Ambassador Anthony Masters have interpreted these statistics, offering a vital public service by giving us the tools we need to make sense of the virus for ourselves and holding the government to account.