Even strong candidates lose 5–8 marks per paper to recurring slips that have nothing to do with ability. On a GL Assessment paper — the dominant 11+ format across most English regions now that CEM's separate tests have been phased out — every question is worth the same single mark, so a careless error on an easy question costs exactly as much as a genuinely hard one you never had time to reach. Cleaning up these avoidable mistakes is the single fastest score-improver available to any child, and unlike learning new content it can happen in a fortnight. This guide walks through the errors that top scorers still make on real papers, why they happen under timed pressure, and the concrete coaching habits that fix them.
Why careless errors matter more than you think
Because 11+ raw scores are converted to a standardised age score (SAS), where roughly 100 is the average for a child's exact age and many grammar schools want around 111 or higher, a handful of dropped marks can be the difference between qualifying and missing out. The scoring is age-adjusted, so summer-born children get a small allowance, but nobody gets marks back for a slip they could have avoided. The reassuring part: careless errors are a process problem, not a knowledge gap. If your child understood the question when you reviewed it calmly afterwards, the mark was lost to technique, and technique is teachable.
The seven mistakes that cost the most marks
Across GL English, maths, verbal reasoning (VR) and non-verbal reasoning (NVR) papers, the same slips recur. Use this table as a quick reference when you mark practice at home — tally which one your child commits most, and target that first.
| Mistake | Where it bites | The fix |
|---|---|---|
| Misreading the question | Maths and comprehension | Underline what is actually asked |
| Answer-sheet mismatch | All multiple-choice papers | Pause before bubbling; check row number |
| Ignoring units | Maths measures | Circle the required unit (m, cm, ml) |
| Leaving blanks | All papers | Never leave an empty bubble |
| Getting stuck on one hard item | Timed sections | Skip, flag, return |
| Rushing the read of the passage | English inference | Read twice; find the exact line |
| Not checking the plausibility of an answer | Maths word problems | Ask "is this sensible?" |
Misreading the question
This is the biggest single leak, and it is especially common in maths: "what is half of 60?" answered as if it read "what is 60 doubled?", or a problem asking for the number of children left over reported as the number in each group. Train your child to underline the actual question — the last few words usually carry the instruction. In comprehension, "which word is closest in meaning" is not the same as "which word appears in the passage", and GL loves that distinction.
Switching letters in multiple choice
On a GL paper the answers are lettered A–E and marked on a separate OMR answer booklet, not next to the question. A child works out that the answer is B, then marks C on the sheet, or slips an entire row when they skip a question without skipping the corresponding answer line. Slowing the marking moment to a single beat — read the letter, find the row number, fill the bubble — eliminates most of these. Practising in true answer-sheet conditions matters, which is why our free mock papers and centre-style centre mocks replicate the separate-booklet mechanics rather than letting children circle answers on the question itself.
Not noticing units
Calculating in centimetres when the answer is required in metres, or giving a time in minutes when the box wants hours and minutes, costs marks on nearly every maths paper. The kilo–metre–centimetre–millimetre ladder trips even confident children under pressure. Teach the habit of circling the unit in the question before the first calculation, and of writing the unit next to the final number so a mismatch jumps out.
Leaving blanks
Every blank is a guaranteed zero. On a five-option GL question a wild guess still gives a one-in-five chance of a mark, and an educated guess after eliminating one or two obviously wrong options is far better than that. The final two minutes of any section are not for perfecting a hard question — they are for making sure no bubble is empty. This is pure free expected value, and coaching it is one of the quickest wins available.
A simple pre-exam checklist you can rehearse
Turn the fixes above into a routine your child runs automatically. Rehearse it during every timed practice so it becomes muscle memory rather than something they have to remember on the day.
- Read the question twice before touching the answer, and underline the instruction.
- Circle the units or the key word ("closest", "not", "difference", "remainder").
- Solve, then sanity-check — is this answer a sensible size?
- Mark the answer deliberately, checking the row number matches the question number.
- Flag and move on if stuck after about a minute; return in the final sweep.
- Fill every blank in the last two minutes, guessing where needed.
A useful mnemonic for the maths word problems specifically is RUCSAC: Read, Underline, Choose the operation, Solve, Answer with units, Check. Children who chant it quietly to themselves make dramatically fewer of the misread-and-ignore-units errors.
Timing and pacing: the errors born of panic
Most careless mistakes are really pacing mistakes. GL papers run at roughly a minute a question for maths and English, and closer to 30–45 seconds each for verbal and non-verbal reasoning, with no time to agonise. When a child spends four minutes wrestling one tricky NVR matrix, they rush the next ten and misread three of them. The cure is to practise the skip-flag-return discipline until it is instinctive, and to sit enough full timed papers that the clock stops feeling frightening. Our revision hub and the timed drills inside the free worksheets library let children build that pacing without any sign-up or paywall. For a fuller walkthrough of exam-day timing, our time management guide breaks the paper into manageable chunks.
How to mark practice like an examiner at home
When you review a completed paper, resist the urge to only count the total. For every dropped mark, ask your child to say why it went — misread, wrong unit, ran out of time, or genuinely didn't know. Keep a simple tally over two or three papers and a pattern emerges fast. If four of five lost marks are misreads, no amount of new content teaching helps; the fix is the underline-the-question habit. This diagnostic marking is what separates children who plateau from those who climb, and it costs nothing but ten focused minutes. Sitting regular mock papers under exam conditions gives you the raw material; the review conversation turns it into improvement. Our companion guide on using mock papers effectively goes deeper on the review routine.
Frequently asked questions
How many marks do careless mistakes really cost?
It varies by child, but 5–8 marks per paper from avoidable slips is common even among able candidates. Because GL scores are standardised and small margins decide grammar-school places, recovering even half of those can lift a borderline result over the line.
Should my child ever leave a multiple-choice question blank?
No. On a GL paper with five options a guess carries a one-in-five chance of a mark, and eliminating one or two options improves that further. There is no penalty for a wrong answer, so an empty bubble simply throws marks away.
My child knows the content but keeps making slips — is that normal?
Completely normal, and it is good news. Slips are a technique problem, not a knowledge gap, which means they respond quickly to the underline-check-mark routine above. A fortnight of deliberate, marked practice usually shows a clear drop in careless errors.