The abacus is awesome, and fun to learn. My parents bought me a miniature one on a trip to San Francisco when I was 8 years old (first time visiting Chinatown).

The abacus is awesome, and fun to learn. My parents bought me a miniature one on a trip to San Francisco when I was 8 years old (first time visiting Chinatown). It came with an illustrated pamphlet and I started practicing with it and figured out how to use it for basic math. I'd recommend it for any kid.