DescriptionMade of premium wood with white letters and numbers, the clock is great for home, classroom, office, etc. As the clock ticks, the hands move around the dial indicating the time of day through a different math problem for each hour. A unique and creative way to keep track of time. This wall clock is a fun and challenging brain exercise. Solve it and you might solve the riddle of time. The perfect gift for teachers, students, engineers and accountants or anyone who works with numbers.Feature- Color: Black._x005F_x000D_- Material: Wood._x005F_x000D_- Size: About 29.7 x 29.7 x 1cm/11.7 x 11.7 x 0.4inch._x005F_x000D_- Made of premium wood with white letters and numbers, the clock is great for home, classroom, office, etc._x005F_x000D_- As the clock ticks, the hands move around the dial indicating the time of day through a different math problem for each hour._x005F_x000D_- A unique and creative way to keep track of time. This wall clock is a fun and challenging brain exercise. Solve it and you might solve the riddle of time._x005F_x000D_- Powered by 1 AA battery(not included), it is easy and convenient to use._x005F_x000D_- The perfect gift for teachers, students, engineers and accountants or anyone who works with numbers.Packing list1 x Creative Mathematics Blackboard Clock Wall Clock Teacher Gift for Classroom Home Office