Is there an infinity of infinities? The question sounds almost absurd, like a child’s riddle meant to twist your brain into ...

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 ...

Nearly twenty years after I graduated high school and my last calculus class, I still get that nightmare where I’m at the exam for a calculus course I somehow forgot to attend, or that I faked my way ...