How many Rubiks cubes have been sold?
I'm curious about the sales volume of Rubik's cubes. Specifically, I want to know how many of these popular toys have been sold globally.
Are Rubiks cubes good for your brain?
I've heard that solving Rubik's cubes can be beneficial for cognitive development, but I'm not sure if it's true. I'm curious to know if playing with Rubik's cubes is actually good for your brain.