Number problems that reward a method rather than a memorised formula: multi-step arithmetic, ratio and percentage sense, rates, and small tables where the trap is measuring against the wrong base. Every puzzle is solvable with mental arithmetic or a few written lines, so no calculator is needed.
What this category trains
Multi-step arithmetic without a calculator
Ratio, fraction and percentage sense
Rate, speed and work reasoning
Reading a small table against the right base
Carrying an intermediate result exactly
25 puzzles · about 60 minutes end to end, as a guide only · untimed
The ladder
The puzzles below run in difficulty order, easiest first. Each one checks on its own and shows its explanation straight away, so you get the method for one rung before you attempt the next.
Work the ladder from the top: the early puzzles need two clean steps, the last three need a named technique and an intermediate value carried exactly. Nothing here is timed and nothing is scored. Try the puzzle, take the hint if you stall, then read the explanation even when you were right — the method is the point, and the same wrong base or off-by-one turns up again and again.
1. Berries before and after lunch
Difficulty 1 of 5 · Warm-up
A market stall opens with 84 punnets of berries. It sells 27 punnets before lunch and 35 punnets after lunch. How many punnets are left at the end of the day?
Show a hint
Subtract the two sales one after the other, then re-read exactly what the question asks you to report.
2. Bulbs shared five to three
Difficulty 1 of 5 · Warm-up
Two gardeners share 96 bulbs in the ratio 5 : 3, with the larger share going to the gardener who dug the beds. How many bulbs does the digger receive?
Show a hint
Count how many equal parts the ratio contains before you divide anything.
3. Weekend-only riders
Difficulty 1 of 5 · Warm-up
A cycling club has 240 members, and 35% of them ride at weekends only. How many members ride at weekends only?
Show a hint
Find 10% first, then scale that up to the percentage you actually need.
4. Five shifts of crates
Difficulty 1 of 5 · Warm-up
Over five shifts a volunteer sorted 8, 9, 15, 18 and 20 crates. What is the mean number of crates per shift?
Show a hint
Add all five values, then divide by how many values you added, not by how many gaps there are.
5. Ribbon cut into lengths
Difficulty 1 of 5 · Warm-up
A roll of ribbon is 4.5 metres long. A craft group cuts it into pieces 25 centimetres long. How many whole pieces do they get?
Show a hint
Put both lengths into centimetres before you do anything else with them.
6. The kettle after the sale
Difficulty 2 of 5 · Straightforward
In a sale, a kettle is reduced by 20% and now costs £36. What was its price before the reduction?
Show a hint
The price you are given is not the whole; it is 80% of the number you are looking for.
7. Jars in three quarters of an hour
Difficulty 2 of 5 · Straightforward
A bottling machine fills 120 jars in 30 minutes at a steady rate. Working at the same rate, how many jars does it fill in 45 minutes?
Show a hint
Work out how many jars a single minute produces, then scale that up.
8. The eight-sector spinner
Difficulty 2 of 5 · Straightforward
A fair spinner has eight equal sectors numbered 1 to 8. What is the probability that a single spin lands on a number greater than 5?
Show a hint
List the sectors that qualify rather than counting them in your head.
9. Six more blue counters
Difficulty 2 of 5 · Straightforward
A tray holds red and blue counters in the ratio 3 : 4, and there are 18 red counters. Six more blue counters are added and no red ones. What is the new ratio of red to blue in its simplest form?
Show a hint
Convert the ratio into real counts of counters first, then add.
10. The L-shaped patio
Difficulty 2 of 5 · Straightforward
An L-shaped patio is a rectangle 8 metres by 5 metres with a rectangle 3 metres by 2 metres removed from one corner. What is the area of the patio?
Show a hint
Find the area of the complete rectangle first, then decide what the corner does to it.
11. Two days of loaves
Difficulty 2 of 5 · Straightforward
The table shows loaves sold at three stalls on each day of one weekend. Across all three stalls, how many more loaves were sold on Sunday than on Saturday?
Loaves sold at three bread stalls over one weekend.
Row
Saturday
Sunday
Rye stall
46
58
Seeded stall
33
29
Plain stall
51
60
Show a hint
Total each day down its own column, and keep the sign of every stall's change.
12. Two painters, one fence
Difficulty 3 of 5 · Tricky
Working alone, one painter takes 6 hours to paint a fence and another takes 12 hours. Working together, each at their own steady rate, how long do they take?
Show a hint
Ask how much of the fence each painter finishes in one hour, then combine those fractions.
13. Up in spring, down in autumn
Difficulty 3 of 5 · Tricky
A subscription price rises by 20% in spring, then falls by 20% in autumn. Compared with the price before the rise, what is the price after the fall?
Show a hint
Set the price at 100 and follow it through both changes, watching which figure each percentage is taken from.
14. Two digits and a reversal
Difficulty 3 of 5 · Tricky
A two-digit number has digits that add up to 11, and reversing its digits gives a number 27 greater than the original. What is the original number?
Show a hint
Reversing a two-digit number changes it by nine times the difference between its digits.
15. A hundred days from Tuesday
Difficulty 3 of 5 · Tricky
A festival stall opens every single day. Today is a Tuesday. What day of the week will it be exactly 100 days from today?
Show a hint
Divide by 7 and use nothing but the remainder.
16. Two classes, one mean
Difficulty 3 of 5 · Tricky
A tutor marks two classes. The 12 learners in the morning class average 60 marks, and the 18 learners in the afternoon class average 70 marks. What is the mean mark across all 30 learners?
Show a hint
The classes are different sizes, so the two means cannot simply be averaged.
17. Mugs and bowls
Difficulty 3 of 5 · Tricky
At a pottery stall, three mugs and two bowls cost £31 altogether, while one mug and two bowls cost £21 altogether. What does one mug cost?
Show a hint
Both purchases contain exactly the same number of bowls; use that to make the bowls disappear.
18. At least one yellow bead
Difficulty 4 of 5 · Hard
A bag holds 5 green beads and 3 yellow beads. Two beads are drawn out one after the other without replacement. What is the probability that at least one of them is yellow?
Show a hint
It is far quicker to work out the chance of drawing no yellow at all, then take that away from 1.
19. Cookery books side by side
Difficulty 4 of 5 · Hard
Five different books are placed in a row on a shelf. Two of them are cookery books and must stand next to each other. How many different arrangements of the five books are possible?
Show a hint
Treat the two cookery books as a single item, then remember they can still swap places inside it.
20. The interrupted ride
Difficulty 4 of 5 · Hard
A courier rides 30 km at 15 km/h, stops for 20 minutes, then rides a further 12 km at 8 km/h. How long does the whole journey take, including the stop?
Show a hint
Time each leg separately with distance divided by speed, converting the decimal part of an hour with care.
21. Three weeks of algae
Difficulty 4 of 5 · Hard
Algae on a pond cover 8 square metres today and the covered area grows by 50% every week. What area do they cover three weeks from today?
Show a hint
Multiply by 1.5 once for each week rather than adding the same amount each time.
22. Offers against applications
Difficulty 4 of 5 · Hard
The table shows one hiring round. Which department made offers to the largest proportion of the people who applied to that department?
Applications received and offers made by four departments in one hiring round.
Row
Applications
Offers made
Design
60
15
Support
80
24
Logistics
200
40
Finance
150
27
Show a hint
Each department has to be judged against its own application total, not against the whole hiring round.
23. The same remainder three times
Difficulty 5 of 5 · Toughest
What is the smallest whole number greater than 1 that leaves a remainder of 1 when it is divided by 4, when it is divided by 5, and when it is divided by 6?
Show a hint
Take the remainder off first and look for the smallest number all three divisors go into exactly.
24. Badges, pens and sixty-one pounds
Difficulty 5 of 5 · Toughest
A club spends exactly £61 on badges costing £3 each and pens costing £7 each, buying at least one of each. It buys more pens than badges. How many pens does it buy?
Show a hint
List every whole number of the dearer item that fits inside the budget, then test each case against the remaining condition.
25. The tank over three days
Difficulty 5 of 5 · Toughest
A tank holds 180 litres of water. On day one a third of the water is drawn off. On day two a quarter of what is then left is drawn off. On day three 25 litres are added. How much water is in the tank at the end of day three?
Show a hint
Each fraction applies to what is left at that stage, not to the amount you started with.
Skills these puzzles practise
Each category maps onto the shared aptitude constructs, so a puzzle that interests you has a lesson and a larger practice bank behind it: