Answer: 1 and 4. They're arranged in groups of two-digit numbers, all ending in 7 and ascending in both rows. Was this a hard math problem, or did you get the answer right? To open this safe ...

While market-working kids in India excel at mental calculations, they struggle with textbook math — while schoolchildren fail ...

A broad new method can help settle this ancient question. In June 1978, the organizers of a large mathematics conference in Marseille, France, announced a last-minute addition to the program. During ...