Pick what you want, print the page. The answer key comes with it, on its own sheet, and it tells you the mistake behind every wrong choice — not just which letter is right.
This exact URL always produces this exact sheet — bookmark it and the answer key will still match next term. Print with your browser; the controls and the site navigation are left off the page.
1.A jacket costs 80 euros. Its price is reduced by 25%. What is the new price?[3]
A20
B40
C45
D55
E60
2.How many different two-digit numbers can be written using only the digits 1, 2 and 3, if a digit may be used twice?[3]
A3
B6
C9
D12
E27
3.How many three-digit numbers can be written using only the digits 1 and 2, with repeats allowed?[3]
A2
B3
C4
D6
E8
4.A sequence begins 7, 11, 15, 19, and continues with the same constant step. What is the 30th term?[3]
A123
B127
C120
D119
E137
5.Two students are chosen from a group of six to represent the class. How many different pairs are possible?[4]
A12
B15
C21
D30
E36
6.What is the units digit of 3 multiplied by itself 100 times, that is 3 to the power 100?[4]
A1
B3
C7
D9
Eit cannot be found without a calculator
7.What is the units digit of 7 multiplied by itself 2026 times, that is 7 to the power 2026?[5]
Ait cannot be found without a calculator
B1
C3
D7
E9
8.Five beads of five different colours are threaded on a circular bracelet. Two bracelets count as the same if one can be turned or flipped into the other. How many different bracelets are there?[5]
A12
B20
C24
D60
E120
9.A machine turns 3 into 7, 5 into 11 and 8 into 17. What does it turn 12 into?[5]
A19
B21
C24
D25
E29
10.You are 20 minutes into a 75-minute paper of 30 questions, still on question 9, and four minutes in with no progress. What is the best move?[5]
AKeep going — four minutes are already invested
BAnswer it with your best guess, mark it, and move on
CSkip it, leave it blank, and come back at the end
DGo back and re-check questions 1 to 8
EJump to question 30 and work backwards
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Answer key — Math Kangaroo practice
Each wrong choice carries the thinking that produces it. When a student picks C, this is what they were doing.
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 — 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.
3.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.
4.A — 123KA-0160Arithmetic sequences and the nth term
BI multiplied the step by 30 instead of by 29, forgetting that the first term needs no steps.
CI used 4 times 30 and forgot to add the starting value.
DI added 28 steps instead of 29, counting the gaps one short.
EI treated the first term as the step and used 7 times 30 minus something close.
5.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.
6.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.
7.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.
8.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.
9.D — 25KA-0106Inferring a rule from examples
AI used the rule add 4, which fits the first example but not the others.
BI found a rule from two examples only and never tested it against the third.
CI doubled the input and forgot the extra one that every example needs.
EI used double and add five, which fits none of the examples exactly.
10.B — Answer it with your best guess, mark it, and move onKA-0126Time triage: now, later, or guess
AI let the time already spent decide, but that time is gone whatever I do next.
CI moved on but left a blank, which scores nothing if I never get back to it.
DI spent time re-reading work I had no reason to doubt, while 21 unseen questions waited.
EI assumed the hardest questions are the best use of time, when the unseen easy ones are worth the same each.