Group by the task being solved
Organize expressions by purpose, such as finding a rate, relating variables or estimating uncertainty. Define every symbol and include units where relevant. Keep similar-looking formulas together with a note explaining what distinguishes them, rather than scattering them across the order in which lectures introduced them.
Record the assumptions and a cue
Beside each formula, state the conditions under which the course uses it and a short problem cue. Add a counterexample where using it would be inappropriate. Check notation with your own course source; the same letter can mean different quantities in different chapters or disciplines.
Test selection before substitution
Take several unlabeled problems and choose the expression before entering numbers. Explain why alternatives do not apply. If notes are not allowed in the exam, practise reconstructing the necessary parts from memory. If a sheet is permitted, confirm its format rules before preparing the final version.
Worked example
An entry for distance = speed × time includes consistent units, a constant-speed assumption and a cue asking whether the rate changes over the interval. A variable-speed problem sits beside it as a boundary case. The student checks unit conversion separately. This is more useful than memorizing the expression while overlooking the conditions needed for a valid answer.
Before you finish
- Symbols, units and conditions accompany important expressions.
- Similar formulas have a selection rule.
- Practice includes choosing a formula without a chapter label.