JAMB maths is timed and entirely multiple-choice, which changes the game compared to a normal school test. There's no partial credit for a correct method with a small slip at the end, a single wrong sign or a misread fraction costs you the whole mark. Below are the five mistakes that come up most often, each with a real example showing exactly where students go wrong, and the specific habit that fixes it.
It's tempting to glance at the four options the moment you read a question, and let them guide your working instead of solving properly first. This backfires badly on questions designed with "distractor" options, wrong answers that come from a specific, predictable mistake, placed there deliberately to catch students who guess or work backwards carelessly.
A student rushing might try x = 5 because "it looks like a round exam answer," without solving. The correct method: 3x = 21 - 6 = 15, so x = 15/3 = 5. In this case guessing happened to work, but on a harder question with less obvious options, that same habit leads straight to a wrong answer chosen with full confidence.
Fix: Solve the question fully on your scratch space first, then look at the options only to match your final answer.
When a term crosses the equals sign, its sign flips, positive becomes negative and negative becomes positive. Forgetting this single rule is one of the biggest sources of wrong answers in algebra questions.
Fix: Write out the sign flip as its own visible step instead of doing it in your head, especially under exam time pressure.
3½ and 3/½ look similar at a glance but mean very different things, a mixed number (three and a half) versus a division (three divided by a half, which equals 6). Under time pressure, this misread happens more than students expect.
Fix: Slow down for one extra second on any question containing a fraction, and say the number out loud in your head before using it.
If your working correctly gives you 8/4, but the four options only show whole numbers like 1, 2, 3, 4, you haven't actually finished the question, you've just stopped solving it one step too early.
Fix: Always simplify fractions, convert improper fractions to the form shown in the options, and check units before circling a final answer.
Time, currency, and measurement questions often deliberately mix units, minutes and seconds, days and hours, kobo and naira, specifically to test whether students convert before calculating rather than after.
Fix: Convert every value in the question to the same unit as your first step, before you touch the actual calculation.
What should I do if none of the four options match my answer?
Don't pick the closest one and move on. Redo your last two steps, a mismatch almost always means a small, fixable slip rather than a wrong method entirely.
Is it worth guessing if I run out of time?
JAMB does not penalise wrong answers beyond simply not scoring that mark, so an educated guess is always better than leaving a question blank, but it should be a last resort, not a first strategy.