Shinken Zemi Ofuro de Battle! Multiplication Table Roulette This is the "Ofuro de Battle! Multiplication Table Roulette," a bonus item from the Shinken Zemi Elementary School Course "Challenge 2nd Grade." When submerged in bath water and then quickly pulled out, the water pressure causes the internal vanes to rotate, randomly displaying multiplication problems. Using the "dan stopper," you can fix the multiplier (the number on the left) and concentrate on practicing specific times tables. This educational toy can be enjoyed by children alone or in a competitive format with parents. There are scratches as the child played with it while studying. Please understand that this is a used item before purchasing.