Imagine hosting a party. You arrange snacks, curate a playlist and place a variety of beers in the refrigerator. Your first guest shows up, adding a six-pack before taking one bottle for himself. You ...

Numeracy or numerosity, the ability to think about and use numbers, varies among human cultures and within populations, much like intelligence does. Many known languages, for example, have no words ...

Students in Melissa Williams' kindergarten class at the Westminster School in Atlanta, Georgia, practice connecting quantities to written numbers — a key part of number sense. Credit: Holly Korbey for ...