Hello, I think this may interest you.

Need to know how random your dice is? This is very important when you want real randomness when you roll a die. Although it may not be the most accurate way to test how random your dice is, one relatively quick test you can do involves just a container, some water, and some salt: Get a container that can fit the die you want to test. Fill the container with water, then add salt and the die to the water – if the die doesn't float, add more salt until the die floats. Flick the die and take note of which side faces upwards – repeatedly flick the dice and record the results.

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