Common 11+ mistakes

A very common mistake is to ignore a zero in the middle of a number. For example, in 3,047 some children think the 4 is in the hundreds place because they skip over the zero. But the zero is there for a reason — it is holding the hundreds place to show there are no hundreds. So the 4 is really in the tens place and is worth 40, not 400. Always count every digit, including zeros, when you work out which place a digit is in.

A very common mistake is to round the digit correctly but then leave the other digits as they are. For example, a child might round 3,472 to the nearest 100 and write 3,500 — so far so good — but then round to the nearest 1,000 and write 3,000 correctly, yet for the nearest 10 write 3,477 instead of 3,470.

This happens because it is easy to forget that the digits after the rounded place must become zeros.

Always check: after rounding, are all the digits to the right of your chosen place zeros? If not, change them to zeros before you write your answer.

A very common mistake is to carry a digit and then forget to include it when you add the next column.

For example, in 3,546 + 2,378, after adding the ones (6 + 8 = 14) you carry 1 to the tens. Some children then just work out 4 + 7 = 11 and forget the carried 1, writing 11 instead of 12.

To avoid this, always write the tiny carried digit clearly above the next column before you add, so you never lose it.

A very common mistake is to forget that 1 and the number itself are always a factor pair. Children often start looking from 2 and miss them.

1 × any number = that number, so 1 and the number are always factors.

Always write down '1 and the number' as your very first pair before you check anything else.

A very common mistake is multiplying a digit correctly and then forgetting to add the small carried number from the previous column.

For example, in 47 × 5: some children write 4 × 5 = 20, and put 20, forgetting to add the 3 they carried. The answer then becomes 205 instead of the correct 235.

How to avoid it: write the carried digit in small writing just above the next column before you do anything else. Then you will see it and remember to add it.

A very common mistake is forgetting to carry the remainder to the next digit. For example, when dividing 52 by 4, some children look at the 5, write 1 above it (because 4 goes into 5 once), and then divide 2 by 4 instead of 12 by 4. They get 13 remainder 0 instead of the correct answer 13. Wait — that one works out the same! Let us use a clearer example: 74 ÷ 3. You look at 7: 3 goes into 7 twice (2 × 3 = 6), remainder 1. If you forget to carry that 1, you divide 4 by 3 and write 1 remainder 1, giving 21 r1. But the correct answer is: carry the 1 to make 14, then 3 goes into 14 four times (4 × 3 = 12), remainder 2, giving 24 r2. Always carry the remainder before moving on.

Some children read the passage once, then answer the question from memory without looking back. This is easy to do, but it often leads to small mistakes — you might muddle a name, a number or a place.

Always look back at the passage to check. The answer is already there for you. Going back is not cheating — it is exactly what you are supposed to do in a comprehension test.

A very common mistake is to confuse adjectives and adverbs.

Children sometimes think that any describing word is an adjective. But remember: an adjective describes a noun, and an adverb describes a verb.

For example, in the sentence She sang beautifully, beautifully is an adverb because it describes the verb sang, not a noun.

Always ask: what is this word describing? If it describes a noun, it is an adjective. If it describes a verb, it is an adverb.

A common mistake is adding -ious instead of -ous — or the other way round.

Why does it happen? Some words really do end in -ious (serious, various, furious), so children add -ious everywhere.

How to avoid it: look at the root word. - If the root ends in a vowel sound, check carefully: vary → various (the y changes to i, so it becomes -ious). - If the root has no extra vowel, just add -ous: nerve → nervous, danger → dangerous.

When you are unsure, try both versions, say them aloud, and pick the one that sounds right. Then check in a dictionary to be sure.

A common mistake is picking any word that is a little bit similar, instead of the closest match.

For example, 'warm' and 'freezing' are both about temperature, but they are opposites — not synonyms!

Always check the meaning carefully. A synonym must point in the same direction as the original word, not just belong to the same topic. When you swap it into the sentence, the meaning should stay the same.

A very common mistake is joining two separate sentences with a comma instead of a full stop. This is sometimes called a 'comma splice'.

Wrong: It started to rain, we ran inside. Right: It started to rain. We ran inside.

Each of those is a complete thought on its own, so each one needs its own full stop. A comma is not strong enough to hold two full sentences together. When you finish one complete idea, stop — use a full stop!

Many children look at the answer options, spot a word they know well, and pick it straight away without checking. This is easy to do because it feels quick and safe.

But a familiar word is not always the right word. It has to match the meaning in that sentence.

Always go back to the sentence and use the swap test, even if you feel sure. One extra check can save you from losing a mark.

A very common mistake is choosing two words that are opposites instead of two words that mean the same thing. For example, some children pick "hot" and "cold" because they often appear together and feel connected. But opposites are not synonyms — they mean very different things!

To avoid this, always ask yourself: "Could I use one of these words instead of the other in a sentence?" If the meaning flips or changes a lot, the words are not synonyms. Use the swap trick every time to catch this mistake before you write your answer.

A very common mistake is picking two words that mean nearly the same thing instead of two that are opposite. This happens because the question includes tricky near-synonyms on purpose.

For example, in the groups (fast, hot, wide) and (narrow, quick, cold), some children pick 'fast' and 'quick' because they know those words go together — but 'fast' and 'quick' mean the same, not the opposite!

Always ask yourself: 'Do these two words pull in opposite directions?' If they feel similar, they are probably a distractor pair. Look again for a pair that truly pulls apart.

A common mistake is joining the words in the wrong order — taking a word from the right group first and a word from the left group second.

The question always tells you: pick one from the LEFT group first, then one from the RIGHT group.

For example, with (rain, sun) + (flower, bow): correct: rain + bow = rainbow ✓ wrong way round: bow + rain = bowrain ✗

Always go left group first, right group second.

A very common mistake is to look at only the first gap, decide on a rule, and then get the answer wrong.

For example, look at this sequence: 2, 6, 7, 11, 12, __

The first gap is +4, so you might think the rule is always +4. But the next gap is +1, then +4, then +1. The rule is actually +4, +1 taking turns.

If you had only checked once, you might have written 16 instead of the correct answer, 16... actually let's be careful — 12 + 4 = 16. In this case it happens to be right, but the pattern could easily mislead you with other sequences.

Try this one instead: 3, 5, 10, 12, 17, __ Gaps: +2, +5, +2, +5 — so the next gap is +2, giving 19, not 22.

Always write out all the gaps. It only takes a few seconds and it keeps you from making this mistake.

Many children look at only the first two numbers in a sequence and guess the gap without checking the others. For example, in 3, 6, 9, 13, ___ a quick glance might make you think the gap is 3 — but look at 9 to 13: that gap is 4! Always check every gap before you write your answer. If the gaps are not all the same, look more carefully — perhaps the gap itself is growing, or you have misread a number.

A very common mistake is to only look at the first letter, then guess the rest.

For example, with the words big, bird, bite, bit — they all start with bi, so you must look at the third letter: g, r, t, t. g comes first, then r, then t. But bite and bit both start with bit, so you need the fourth letter: e or nothing. A shorter word comes first if all its letters match the start of the longer word, so bit comes before bite.

Always keep comparing, one letter at a time, until you find a difference.

A common mistake is to rush and pick an answer the moment something looks slightly different, without checking all four figures.

For example, you might notice figure A looks big and quickly choose A — but you have not checked whether B, C and D are all small. Maybe A is big AND has different shading too. The real odd one out might be a different figure for a different reason.

How to avoid this: always check the feature across all four figures before writing your answer. Ask yourself, "Do the other three all share this feature?" Only move on when you are sure.

A common mistake is to look only at the third box and guess what might come after it, without checking whether the same change happened from box 1 to box 2. You might spot the wrong rule and choose the wrong answer.

Always check that your rule works for every step in the row — from box 1 to box 2, and from box 2 to box 3. If it works every time, you can be confident.

A very common mistake is to flip the shape in the wrong direction. For example, with a vertical mirror line, some children accidentally flip the shape up and down instead of left and right.

This happens because it can feel confusing which way to go.

To avoid it, always ask yourself: which way does my mirror line run? If the line is vertical (up-down), the flip goes left-right. If the line is horizontal (across), the flip goes up-down. Say it to yourself before you start each question.

The most common mistake is choosing a reflected shape by accident, thinking it has just been turned.

This happens because after a half turn (180°), some shapes look very similar to their reflection, so it is easy to mix them up.

How to avoid it: always track one detail that is clearly on one side — like a dot, a shaded part, or a pointed tip. After a rotation, that detail stays on the same side of the shape relative to the shape's body. After a reflection, it swaps to the opposite side. If you track your chosen detail carefully, you will not be fooled.

Many children confuse a reflection with a rotation. They see that a shape looks different and guess it has been rotated, when really it has been flipped — or the other way round.

Here is how to tell them apart. A rotation keeps the shape the same way round — imagine turning a book on a table. A reflection flips the shape — imagine holding the book up to a mirror.

With an L-shape or arrow, look at which corner or point is at the top after the change. If the shape looks like it has been turned, it is probably a rotation. If it looks like a mirror image — where left and right have swapped — it is a reflection. Take your time and compare corner by corner.

A very common mistake is to choose an answer that looks just like Shape C, without making any change to it. This happens when you look at the answer choices before you have worked out the rule.

Always work out the rule first. Then check that your answer really does apply the rule to Shape C. If your chosen answer looks identical to Shape C, something has gone wrong — go back and look at A and B again.