Clock Arithmetic Demonstration Set the number of hours on the clock with the slider control, then type in the number you want to add, subtract or multiply and press the appropriate button. The standard clock has the greatest hour on top. The zero clock has a zero on top. The tables in the upper right show addition and multiplication of the hours on the clock. The zero clock's tables are different from the standard clock's tables. Can you find any similarities? (Hint  Does zero on the zero clock behave like the top number on a standard clock?) You can use clock arithmetic to make quiltlike art. Click here to see how. 
