"Math Dial" Watch Shows Pop Quiz Equations At Each Hour Indicator on the Black Dial of the Brushed Chrome Watch with Black Leather Strap The "Math Dial" theme watch has a unisex size 36mm round brushed chrome case with a black leather strap. Designed with a blackboard black dial that shows a pop quiz math equation at each hour indicator. Perfect gift for a math or physics student, math enthusiast or numerologist.