Worksheet generator

1.A — the rectangleKA-0004Line and rotational symmetry

• BI found the vertical fold that works and assumed a second one must work as well without testing it.
• CI saw that the star looks very symmetric and picked it without counting how many lines of symmetry it actually has.
• DI counted the horizontal fold and then counted the vertical one too, even though the two halves do not match.
• EI only tested vertical folds on every shape and concluded that no shape had two lines.

2.B — the straight line of sixKA-0048Nets and folding, 2D to 3D

• AI assumed any arrangement that is not a simple line must fail to fold.
• CI thought a staircase would overlap when folded, without tracking a single face through the fold.
• DI picked the cross because it looks unusual, even though it is the most familiar cube net there is.
• EI checked that each arrangement had six squares and assumed six squares is enough.

3.C — 5KA-0061Operation puzzles and cryptarithms

• AI solved for the triangle and gave that instead of the square.
• BI found the triangle is 4 and gave that number, without going on to the second equation.
• DI halved the 12 instead of dividing it by the three triangles.
• EI subtracted the wrong way round, taking 9 from a number instead of taking the triangle from 9.

4.B — 75KA-0088Angles on lines, in triangles, in polygons

• AI added the three angles wrongly, getting 295 instead of 285.
• CI used an angle sum of 370, mis-remembering the total for a quadrilateral.
• DI repeated one of the given angles instead of computing the missing one.
• EI used the triangle's 180 degrees and then adjusted, rather than the quadrilateral's 360.

5.A — 12KA-0110Bar models for part–whole

• BI split the 48 into three parts instead of the four the bars actually make.
• CI halved the total, as if the two of them had the same number each.
• DI found Bo's share correctly but then gave Ana's number instead.
• EI gave Ana's total, which is three of the four boxes, rather than Bo's one.

6.B — 280KA-0114Money and change

• AI subtracted the cost of one notebook rather than all three.
• CI bought two notebooks instead of three.
• DI gave the total cost of the notebooks instead of the change.
• EI converted the 10 euro note to 1000 cents but subtracted the price of only one notebook after doubling it.

7.B — 8KA-0119Find what is actually being asked

• AI halved the difference, as if the question asked how many Bo should hand over to make them equal.
• CI gave how many Bo has now rather than how many more he has than Ana.
• DI gave the number Bo started with, without doing anything.
• EI added the two amounts together instead of comparing them.

8.C — 4KA-0120Draw the diagram

• AI assumed the walk was a loop because the north and south distances match.
• BI gave one of the distances walked rather than the distance from the start.
• DI added the two different directions together instead of drawing where the cat ends up.
• EI added up the whole distance walked, which is not the same as the distance from the start.

9.B — Write an answer for every one of themKA-0127Never leave a blank — there is no penalty

• AI treated guessing as dishonest, but the rules of the paper explicitly allow it and cost nothing.
• CI answered one and left two blanks that could each have scored, at no risk.
• DI tried to communicate with the marker, but only the answers are scored.
• EI offered working on a paper where only the chosen letter is marked.

10.B — 76.80 poundsKA-0153Percentages and simple discounts

• AI assumed a 20 percent rise and a 20 percent fall must cancel because the percentages match.
• CI applied only the fall and forgot the rise.
• DI got the size of the change right but the direction wrong.
• EI applied only the rise and forgot the fall.

11.C — 16KA-0019Multi-step arithmetic word problems

• AI found what one child has left and gave that instead of the total for all four.
• BI divided 24 by 4 and then subtracted 2 twice, mixing up per-child steps with total steps.
• DI subtracted 2 pencils once from the whole pack instead of once from each of the four children.
• EI subtracted the 2 before sharing, so only one lot of 2 ever came out of the total.

12.C — 9 timesKA-0042Scaling and similar figures

• AI applied the length scale factor straight to the area.
• BI doubled the scale factor because area involves two dimensions, instead of squaring it.
• DI multiplied the scale factor by four, as though area scaled with the number of sides.
• EI cubed the scale factor, which is the rule for volume rather than area.

13.D — 24KA-0073Arrangements of a few objects

• AI counted the letters rather than their arrangements.
• BI multiplied 4 by 3 and stopped, forgetting the last two positions.
• CI used 4 choices for every position, as if letters could repeat.
• EI used 4 choices in each of four positions, which allows every letter to repeat.

14.B — 15KA-0074Selections of a few objects

• AI doubled the group size instead of counting pairs.
• CI allowed a student to be paired with themselves, adding six impossible pairs.
• DI counted each pair twice, once in each order, and forgot to halve.
• EI multiplied 6 by 6, counting every ordered pair including a student with themselves.

15.D — 6KA-0085Line and rotational symmetry

• AI checked only the vertical and horizontal folds and stopped there.
• BI counted the lines through opposite corners and forgot the ones through opposite edges.
• CI assumed a hexagon behaves like a rectangle with a couple of extra folds.
• EI counted each line twice, once from each end.

16.B — Bo onlyKA-0096Truth-tellers and liars

• AI took Ana's statement at face value without checking whether a truthful person could say it.
• CI decided nobody was lying without testing Ana's statement against that assumption.
• DI believed Ana's statement even after concluding she was a liar, which is what a liar's statement cannot be.
• EI gave up when Ana's statement looked circular, instead of testing one assumption all the way through.

17.B — 21KA-0104Recursive rules

• AI counted the two starting terms as one, so I stopped at the seventh term.
• CI added the two before it but slipped once in the middle of the chain.
• DI generated one term too many and gave the ninth.
• EI doubled each term instead of adding the two before it.

18.B — 7KA-0131Back-solve from the answer choices

• AI tested the first choice, got 13, and picked it anyway because it was close.
• CI added the 3 to 17 instead of subtracting it, then halved the 20 that gave me.
• DI subtracted 3 from 17 and gave that without halving it.
• EI added 3 to 17 instead of undoing the addition by subtracting it.

19.C — 8KA-0147Circles: radius, diameter, and touching circles

• AI subtracted the radii, which is the answer when one circle sits inside the other.
• BI averaged the two radii instead of adding them.
• DI multiplied the radii together rather than adding them.
• EI added the two diameters instead of the two radii.

20.B — 50 sq cmKA-0164Scaling and similar figures

• AI scaled the area by 5/3, using the side ratio directly instead of its square.
• CI multiplied the area by 2.5, halfway between the side ratio and its square.
• DI scaled by 3/5 instead of 5/3, making the larger triangle smaller.
• EI multiplied by 5 and ignored the 3 in the ratio entirely.

21.A — 40 percentKA-0165Mixtures and weighted averages

• BI averaged 25 and 50 without weighting by how much of each solution there was.
• CI added the two percentages together, which cannot be right because a mixture can never be stronger than its strongest ingredient.
• DI weighted the percentages by the wrong volumes, giving the 25 percent solution the larger share.
• EI used only the acid from the weaker solution and spread it over all ten litres.

22.C — 4KA-0020Paper folding and hole punching

• AI forgot that the punch goes through every layer at once, not just the top one.
• BI undid only one of the two folds before counting the holes.
• DI doubled for the first fold and then added two more rather than doubling a second time.
• EI counted a fold that was never made, doubling three times instead of twice.

23.E — 9KA-0037Last-digit behavior of products and powers

• AI assumed a number this large has no reachable last digit and gave up on the cycle.
• BI found the cycle 7, 9, 3, 1 but used a remainder of 0 when the remainder is actually 2.
• CI found the cycle but counted its positions starting at zero, shifting my answer along by one.
• DI assumed the units digit of any power of 7 is always 7.

24.B — 0.2KA-0052Area by subtraction (shaded regions)

• AI estimated by eye from the four corner pieces without comparing them to the whole square.
• CI used a diameter of 5 instead of a radius of 5 when working out the circle's area.
• DI assumed the circle covers half the square because it touches all four sides.
• EI found the fraction covered by the circle and gave that instead of the fraction outside it.

25.A — 12KA-0071Overcount, then correct

• BI divided the 120 arrangements by 6 rather than by the 10 movements that leave a bracelet looking the same.
• CI allowed for turning the bracelet but forgot it can also be flipped over.
• DI halved the 120 for flipping but forgot that turning also gives the same bracelet.
• EI counted every arrangement in a line, as if the bracelet had a fixed first bead.

26.D — No, because the number of moves is oddKA-0097Parity arguments

• AI assumed enough moves can undo anything, without asking what each move preserves.
• BI tried a few sequences that nearly worked and assumed a better choice would finish the job.
• CI reached for the number of items rather than for what a single swap actually changes.
• EI thought the choice of swaps could change the outcome, when every swap has the same effect.

27.B — Read all ten quickly, pick the two or three that look most doable, and fill in every answer before the endKA-0130Managing the 5-point block

• AI worked in order, so a hard early question could eat the time meant for easier later ones.
• CI assumed the hardest question is worth the most, but every question in this block scores the same.
• DI used length as a proxy for difficulty, which is not reliable in this block.
• EI spread the time equally, which is too little for the questions I could do and wasted on the ones I could not.

28.D — DeeKA-0136Ordering and ranking from clues

• AI ignored the very first clue, which rules Ana out of the front directly.
• BI put Bo at the front, but Bo must have Ana immediately in front of him.
• CI forgot that Cal is fixed at the back of the line.
• EI stopped once two arrangements seemed possible, without testing whether the second one actually fits every clue.

29.C — 4KA-0140The multiplication principle

• AI counted the codes that do start with A rather than the ones that do not.
• BI counted the letters available for the first position instead of counting whole codes.
• DI counted every arrangement of the three letters and forgot the restriction.
• EI allowed letters to repeat, which the words each exactly once rule out.

30.A — 120KA-0166Counting up to symmetry

• BI counted every arrangement in a row, so each circular seating got counted once for every rotation.
• CI divided 720 by 20 or some other number instead of by the 6 rotations.
• DI divided by 12, treating reflections as identical too, though the question only allows rotations.
• EI fixed two people rather than one, dividing by an extra factor.