May 30 (UPI) --A shard of smooth bone etched with irregular marks dating back 20,000 years puzzled archaeologists until they noticed something unique - the etchings, lines like tally marks, may have ...

Prime numbers are tricky things. We learn in school that they’re numbers with no factors other than 1 and themselves, and that mathematicians have known for thousands of years that an infinite number ...

The online computer game “Is this prime?” tests a player’s knowledge of prime numbers—and just surpassed 2,999,999 attempts. Give it a whirl. The Greek mathematician Euclid may very well have proved, ...