A new history of mathematics focusing on the marginalized voices who propelled the discipline, spanning six continents and thousands of years of untold stories. Mathematics shapes almost everything we do. But despite its reputation as the study of fundamental truths, the stories we have been told about it are wrong—warped like the sixteenth-century map that enlarged Europe at the expense of Africa, Asia and the Americas. In The Secret Lives of Numbers, renowned math historian Kate Kitagawa and journalist Timothy Revell make the case that the history of math is infinitely deeper, broader, and richer than the narrative we think we know. Our story takes us from Hypatia, the first great female mathematician, whose ideas revolutionized geometry and who was killed for them—to Karen Uhlenbeck, the first woman to win the Abel Prize, “math’s Nobel.” Along the way we travel the globe to meet the brilliant Arabic scholars of the “House of Wisdom,” a math temple whose destruction in the Siege of Baghdad in the thirteenth century was a loss arguably on par with that of the Library of Alexandria; Madhava of Sangamagrama, the fourteenth-century Indian genius who uncovered the central tenets of calculus 300 years before Isaac Newton was born; and the Black mathematicians of the Civil Rights era, who played a significant role in dismantling early data-based methods of racial discrimination. Covering thousands of years, six continents, and just about every mathematical discipline, The Secret Lives of Numbers is an immensely compelling narrative history.