Math puzzles are a fun way to keep your brain sharp and active. Just like physical exercise is good for your body, mental exercise is very important for your brain health– that’s why missing number ...

Pens, pencils and a facility with numbers. Also helpful: earplugs, plushies, a water bottle, calming herbal oil and the occasional “wild bifurcation” (a.k.a. a wild guess). Competitors at the World ...