Others already gave good answers but I want to point out just one thing: the precedence rule is purely syntactical (i.e. computer decides it from only the text).  What those methods actually do is irrelevant.

For example, you can define a method called **, such as:

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** aNumber

   ^ self raisedTo: aNumber.

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and then, you can write:

2 ** 3 + 1

to get 9.