Worksheet generator

1.B — square 3KA-0005Nets and folding, 2D to 3D

• AI picked the square directly next to the shaded one in the net, but neighbours in the net share an edge on the cube.
• CI counted to the far end of the column, assuming the square furthest away in the net is the one opposite.
• DI picked one of the side flaps because it is not touching the shaded square in the drawing.
• EI picked the other side flap for the same reason, without tracking what happens as the net folds.

2.B — 2KA-0016Dice and cube face relationships

• AI used the upper die's touching face instead of the lower one, so I worked from 3 rather than 5.
• CI gave the number on a touching face itself rather than the number opposite it.
• DI subtracted 3 from 7 because I confused which die was sitting on which.
• EI gave the lower die's upward face, which is the number I was told, not the hidden one underneath.

3.D — 15KA-0024Ratio as parts of a whole

• AI found what one part is worth and gave that as my answer instead of multiplying it back up.
• BI divided 40 by the five blue parts instead of by the eight parts that make the whole.
• CI read the ratio 3 to 5 as meaning 3 out of every 5 and worked from that.
• EI found the value of one part correctly but then multiplied by 5 instead of 3, giving the blue counters.

4.C — 61KA-0030Arithmetic sequences and the nth term

• AI added the step 18 times, counting the gaps between terms one too few.
• BI multiplied the step of 3 by 20 and forgot that the first term is already in place.
• DI used a first term of 3 instead of 4 while adding 20 steps.
• EI added the step 20 times to the first term instead of 19 times.

5.A — 1KA-0053Remainders and modular cycles

• BI found the cycle 2, 4, 1 but read the remainder of 30 divided by 3 as one instead of zero.
• CI counted the cycle positions from zero, which shifted my answer one step along.
• DI divided 30 by 7 and used that remainder rather than the remainder of the powers.
• EI assumed the remainder would be one less than the divisor because the power is large.

6.B — 10KA-0087Scaling and similar figures

• AI added the difference between the areas' square roots to the side rather than multiplying by their ratio.
• CI doubled the side because the larger area is roughly double the smaller.
• DI used the ratio of the areas as if it were the ratio of the lengths, then adjusted.
• EI multiplied the side by the ratio of the areas divided by three, mixing up which ratio applies to lengths.

7.B — BoKA-0092Ordering and ranking from clues

• AI gave the child who is first rather than the one who is second.
• CI placed Cal directly after Ana, reading ahead of Dee as meaning immediately ahead.
• DI built the order backwards from the last position instead of forwards from the first.
• EI assumed the clues left several orders open without checking that they chain into a single one.

8.C — 55KA-0107Growth patterns and figurate numbers

• AI stopped at the eighth triangle, losing count while adding the rows.
• BI gave the ninth triangle instead of the tenth, being one row short.
• DI gave the eleventh triangle, adding one row too many.
• EI squared the position number, which describes square patterns rather than triangular ones.

9.A — 12KA-0122Back-solve from the answer choices

• BI assumed a number with two different prime factors always has six factors.
• CI counted the factors of 16 as six by including a number twice.
• DI assumed a square number has six factors without listing them.
• EI counted the powers of 3 up to 27 and thought there were six of them.

10.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.