Tag each mistake as diagram, formula, algebra or arithmetic — then drill that tag.
Key formulas
Four bins
Diagram misread, wrong formula, algebra slip, calculator/arithmetic slip. Most students over-blame “careless” without naming the bin.
Rewrite the rule
For each error write one sentence you will check next time: “Height must be perpendicular to the base I chose.”
Retest
Three days later, attempt a fresh question of the same type without notes.
Worked example
Worked example
Problem. You used a pyramid’s slant edge as the height and got V too large. Write a one-line error-log entry.
Solution. Bin: formula/conditions. Rule: “Mark the perpendicular height before substituting into V = (1/3)Ah.” Retest with a question that gives a lateral edge only.
Sample entry
Used slant edge as pyramid height → bin: formula/conditions → rule: mark ⊥ first.
Review quiz
Best next step after logging a diagram misread is:
Practice questions
- Create an error-log template with four headings.
- Convert one past mistake into a one-sentence rule.
Study notes
How long should an entry be?
Four lines: question id, wrong step, bin, future rule.