Worksheet generator

1.C — 4KA-0001Counting by position (sliding window)

• AI split the board into separate 2 by 2 blocks and only one whole block fitted, so I answered one.
• BI slid the square across the top row and found two positions, then forgot it can also move down.
• DI counted the four sliding positions and then added the two whole rows of the board as well.
• EI counted the nine small squares on the board instead of the 2 by 2 squares.

2.B — 28KA-0035Handshakes and pairs

• AI doubled the number of people, as if each person made two handshakes in total.
• CI let each person shake hands with all eight people including themselves before halving.
• DI multiplied 8 by 7 and forgot that each handshake was counted from both sides.
• EI multiplied 8 by 8, counting every ordered pair including a person with themselves.

3.C — 14KA-0051Complementary counting

• AI counted the multiples of 3 and gave that instead of the numbers that are not multiples.
• BI counted 21 as a multiple of 3 inside the range, so I removed one too many.
• DI removed only the multiples of 3 that are also even, so I subtracted three instead of six.
• EI gave the size of the whole range and forgot to remove anything at all.

4.C — 6KA-0054Counting shapes hidden inside a figure

• AI counted only the three small rectangles drawn as separate cells and stopped there.
• BI counted the three small rectangles and the whole one, and forgot the two made of two cells.
• DI counted a rectangle made of the left and right cells, even though they are not next to each other.
• EI assumed any pair of the four vertical lines makes a rectangle without checking each one.

5.C — 6KA-0067Tree diagrams

• AI counted the puddings only and forgot that the main course is also a choice.
• BI added the number of mains to the number of puddings instead of multiplying them.
• DI used three puddings as well as three mains, without reading how many puddings there are.
• EI doubled the answer, as if the order of the two courses made a different meal.

6.C — 9KA-0072Systematic listing

• AI counted only the numbers with two identical digits, like 11, 22 and 33.
• BI required the two digits to be different, even though repeats are allowed.
• DI allowed a fourth digit that was not in the list.
• EI counted three-digit numbers instead of two-digit ones.

7.E — 8KA-0143Systematic listing

• AI counted the two available digits rather than the numbers they can build.
• BI counted the three positions instead of the numbers.
• CI used only two of the three positions when multiplying.
• DI multiplied 2 by 3, mixing the number of digits with the number of positions.