Perfect for use at home or in a classroom, this math wall clock displays simple equations in place of mere numerals for each hour. Instead of 3 o’clock, you get “9÷3.” In place of 7 o’clock, it shows “9+(-2)”. Perhaps most cleverly, 1 o’clock reads as 30°, since that indicates the angle between each hour (at least on a circular 12-hour clock like this).

The next time a kid asks, “What am I ever going to use this math for???” you can simply answer, “So you can tell the time, silly!”

Get this neat wall clock for $22 on Amazon.