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.Ana adds up the first seven odd numbers: 1 + 3 + 5 + 7 + 9 + 11 + 13. Is her total odd or even, and what is it?[3]
Aodd, 47
Bodd, 49
Ceven, 48
Deven, 49
Eodd, 45
2.On the number line shown, the marks are equally spaced. What number does the arrow point to?[3]
Text description of the figure
A number line with equally spaced tick marks. The leftmost tick is labelled 0 and the rightmost is labelled 60, with five unlabelled ticks evenly spaced between them. An arrow points to the fourth tick from the left.
A4
B24
C30
D40
E50
3.In the number 4073, what is the value of the digit 7?[3]
A3
B7
C70
D700
E4000
4.What is 1 + 2 + 3 + ... + 20?[3]
A190
B200
C210
D220
E420
5.Each shape stands for a whole number. A triangle plus a triangle plus a triangle is 12, and a triangle plus a square is 9. What is the square?[3]
A3
B4
C5
D6
E8
6.The four-digit number 27_4 is divisible by 3. Which digit could go in the gap?[4]
A1
B2
C3
D4
E6
7.The two digits of a number are swapped and the number gets bigger by 36. Which of these could be the number?[4]
A13
B15
C24
D41
E62
8.Which of these numbers can be divided exactly by both 4 and 9?[4]
A96
B117
C132
D144
E153
9.How many two-digit numbers have both of their digits odd?[5]
A10
B20
C25
D45
E50
Kangaroo Atlas · https://kangaroo-atlas.vercel.app · seed 1 · CC BY-NC-SA 4.0 · Independent project, not affiliated with Math Kangaroo in USA, NFP.
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.B — odd, 49KA-0002Parity of numbers (odd/even behavior)
AI decided that adding odd numbers always keeps the total odd, and made an arithmetic slip as well.
CI paired the numbers up and forgot that with seven numbers one is left over, so I expected an even total.
DI added correctly but then labelled 49 as even because I had already decided the pairs would make it even.
EI added only the first six numbers and stopped before including the thirteen.
2.C — 30KA-0006Number lines and betweenness
AI counted the tick marks and gave the position number instead of reading the value on the scale.
BI worked out that each gap is worth 10 but then counted only as far as the tick before the arrow.
DI counted the tick marks rather than the gaps between them, so every gap came out one step too small.
EI counted the gaps from the right-hand end instead of from zero.
3.C — 70KA-0055Place value and digit positions
AI gave the last digit of the number instead of looking at the 7 at all.
BI gave the digit itself rather than what it is worth in the position it sits in.
DI counted the positions from the left, so I read the 7 as being in the hundreds place.
EI gave the value of the largest digit instead of the value of the 7.
4.C — 210KA-0057Clever regrouping (pair to round numbers)
AI paired the numbers from the outside in but left the 20 out of every pair, so I added only up to 19.
BI estimated the total as a round number instead of working it out.
DI used eleven pairs of 20 instead of ten pairs of 21.
EI multiplied 20 by 21 and forgot that pairing counts every number twice.
5.C — 5KA-0061Operation puzzles and cryptarithms
AI solved for the triangle and gave that instead of the square.
BI found the triangle is 4 and gave that number, without going on to the second equation.
DI halved the 12 instead of dividing it by the three triangles.
EI subtracted the wrong way round, taking 9 from a number instead of taking the triangle from 9.