Wooden Wall Clock: The math clcok is made of MDF wood, each hour marked by a simple math equations. Large white bold numerals against black face creates easy viewing from a distance and every angle.Easy to Read. Silent : Non-ticking accurate quartz movement, which ensure a silent environment for your sleeping and working without any ticking sounds. Easy to Use: Powered by 1 AA battery(Not included),a hook included . We recommend using carbon batteries instead of alkaline batteries.Note：Insert into (+) first, then insert into (-). Decorative Clock: It is suitable for classroom,study room,kids room,bedroom,accountant's or engineer's office etc. Great Gift Idea:Not only a time keeper, the clock functions as a fun gifts.It can also be used as a nice gifts for math nerds/enthusiast,math teachers,accountant,engineer etc.