Numberphile revived an ancient multiplication trick—halves and doubles—also called Egyptian or Russian math, where you repeatedly halve one number and double the other. After crossing out rows with ...

Vikki Velasquez is a researcher and writer who has managed, coordinated, and directed various community and nonprofit organizations. She has conducted in-depth research on social and economic issues ...

Because the Smithsonian museums are free, we cannot base our visit tallies on a number of tickets sold. The counts sometimes include staff, as well as visitors who leave the museum and return. A ...