explain sizes (scales) of remote control cars?

I'm looking for remote control cars on Ebay. I see various scales, 1:10, 1/18, 1/12, etc.
Can someone give me a complete table of the sizes and what they mean as far as length of the car.
The child doesn't want some matchbook size car so something around 10-12 inches long. Explain these scales and sizes. Thanks.

1/24 means that it's on a scale of 1 to 24 compared to the real thing. (it takes 24 of the toy cars to match the length of 1 real car)

Matchbox cars are on a 1/64 scale.

so if you want something 10-12 inches long, 1/10 1/12 and 1/18 should be about fine.