Worksheet generator

1.C — 55 degreesKA-0022Angles on lines, in triangles, in polygons

• AI assumed the triangle was isosceles because it had a right angle, so I repeated the 35.
• BI assumed a right-angled triangle always has two 45 degree angles.
• DI subtracted 35 from 100 instead of from 90, mixing the angle sum up with a round number.
• EI subtracted only the 35 from 180 and forgot to take off the right angle as well.

2.E — 24KA-0038Building and counting with unit cubes

• AI added the three measurements together instead of multiplying them.
• BI counted one layer of 4 by 3 and forgot that the block is two layers tall.
• CI read the block as 3 by 3 by 2 because the drawing hid the far column.
• DI counted only the cubes whose faces I could actually see in the picture.

3.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.

4.C — HKA-0142Line and rotational symmetry

• AI found the vertical fold and assumed a horizontal one must work too.
• BI found the horizontal fold and stopped without testing the vertical one.
• DI counted the vertical fold twice rather than testing a horizontal one.
• EI mistook turning the letter upside down for folding it, which is rotation rather than symmetry about a line.

5.C — 84KA-0027Area by subtraction (shaded regions)

• AI gave the area of the square that was cut out instead of the area that remains.
• BI subtracted the side length of the small square from the area of the big one.
• DI subtracted 4 rather than the small square's area of 16.
• EI gave the area of the whole square and forgot that a piece had been removed.

6.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.

7.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.

8.D — 120KA-0148Clock geometry: hands, angles, times

• AI gave the angle for a single hour mark rather than the four marks between the hands.
• BI counted two hour marks instead of four.
• CI assumed any gap of a few hours is a right angle, as it is at three o'clock.
• EI measured the angle the long way round the clock face instead of the smaller one.

9.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.

10.B — 10KA-0082Shortest paths on and around shapes

• AI measured the straight line through the middle of the room, but the ant has to stay on the surfaces.
• CI unfolded the room but folded out the short wall rather than the one that makes the shortest route.
• DI chose an unfolding that gives a longer straight line and did not compare it with the others.
• EI walked along the edges of the room, 8 then 4 then 2, instead of cutting straight across the surfaces.