I bought this abacus for $2.99 at the thrift store last week. Damian was having a little trouble with money. He couldn't grasp the concept that if you paid $1.00 for an item, but the item cost $.70, you would get back $.30. After trying this out on the abacus a few times he was able to understand. I would recommend this for any child who may need to visualize math concepts.