Worksheet generator

1.E — 60KA-0026Percentages and simple discounts

• AI worked out the size of the discount and gave that as the new price instead of subtracting it.
• BI treated a quarter off as half off and took the price down to 40.
• CI applied the 25% reduction twice, taking 80 down to 60 and then 60 down to 45.
• DI subtracted 25 euros rather than 25 percent, treating the percentage as an amount of money.

2.C — 9:36KA-0041Factors, multiples, LCM and GCD by listing

• AI found the greatest common divisor of 12 and 18 instead of the least common multiple.
• BI added the two intervals together rather than looking for a time that is a multiple of both.
• DI found a common multiple but not the least one, landing on a later coincidence.
• EI multiplied the two intervals together instead of finding their least common multiple.

3.D — 4320KA-0059Estimation and order of magnitude

• AI worked out the drips in an hour and stopped there.
• BI multiplied by the 24 hours but forgot the 60 minutes in each one.
• CI used 6 hours in a day, thinking of waking hours rather than a whole day.
• EI used 600 minutes in an hour rather than 60.

4.C — 2/5KA-0141Number lines and betweenness

• AI compared the bottom numbers and assumed a bigger denominator means a bigger fraction.
• BI saw that 4 lies between 3 and 2 and assumed one quarter therefore lies between the two fractions.
• DI checked that it is bigger than one third but never checked it against one half.
• EI compared the top numbers only and ignored what the bottoms do to the size.

5.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.

6.D — 2550KA-0058Clever regrouping (pair to round numbers)

• AI found the sum of 1 to 50 and forgot that every term here is twice as big.
• BI used 49 pairs instead of 25, losing one pair from the count.
• CI estimated the answer as a round number rather than pairing properly.
• EI paired the terms but forgot that pairing counts every number twice, so I never halved.

7.C — 12KA-0062Factors, multiples, LCM and GCD by listing

• AI found a number that divides both but not the largest one, stopping at the first that worked.
• BI used the difference between 36 and 24 divided by 2 rather than a common factor.
• DI used a factor of 36 without checking that it also divides 24.
• EI found the least common multiple instead of the greatest common divisor.

8.C — 11KA-0066Means, and working backwards from a mean

• AI assumed the missing number must be the mean itself.
• BI averaged the three known numbers instead of working from the total.
• DI repeated one of the numbers already given rather than computing the missing one.
• EI used a total of 37 instead of 36, adding the mean in once too often.

9.A — 1KA-0149Last-digit behavior of products and powers

• BI assumed every power of 3 ends in 3.
• CI found the cycle 3, 9, 7, 1 but counted its positions from zero, landing one step early.
• DI used a remainder of 2 instead of 0 when dividing 100 by the cycle length of 4.
• EI assumed a number this large has no reachable last digit, rather than looking for a repeat.

10.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.