What acronyms did you use in school? You know, like PEMDAS?
'My very eager mother just served us nine pizzas.' - For the planets
[Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto]
'I pet monkeys at the circus' - For the phases of mitosis
[Interphase, Metaphase Anaphase, Telophase, Cytokinesis]
And of course;
'Please excuse my dear aunt sally' - For the order of operation
[Parentheses, Exponents, Multiplication, Division, Addition, Subtraction]