Science quiz
Number criteria: one number fits them all
The numbers 1 to 36 are on the board. Each prompt gives two or three criteria that only one number meets. Twelve prompts, two tries each.
- Format
- Pick the match
- Items
- 12 to match
- Limit
- 4:00
- Level
- Medium
- Checked
- 2026.10.03
- Prompts
- 12
- Bank
- Number buttons, A to Z
- Time limit
- 4:00
- A miss
- 2 tries, then the answer is shown
- Each criteria appears in turn. Click its match in the bank.
- Used answers leave the bank. Keys 1 to 9 pick the first nine buttons; type a name to jump to it.
- Skip (0) sends a prompt to the back of the queue.
- Pause whenever you like (Esc). The board hides while the clock is stopped.
Click the one number that fits every criterion. The bank appears when you start.
About this quiz
Every prompt is a small sieve: each criterion leaves some of the 36 numbers standing, and together they leave exactly one. No criterion is spare; drop any one of them and a second number fits.
- Twelve prompts lead to twelve different numbers.
- A number that has been found leaves the board, which makes the later prompts a little easier.
- 1 is a square, a cube, a triangular number and a Fibonacci number, but it is not prime.
More quizzes like this
| No. | Quiz | Section | Format | Items | Added |
|---|---|---|---|---|---|
| 01 | Number Venn diagram: 1 to 60 Even, prime, square, triangular: three circles, eight regions and eight numbers from 1 to 60 to place. Click the region where each number belongs. Science / Venn diagram / 8 to place | Science | Venn diagram | 8 | 2026.10.03 |
| 02 | Solar system criteria: one world fits them all Spins backwards, less dense than 2 g/cm³, one of the eight planets? Each prompt lists two or three criteria that only one world meets. Click it. Science / Pick the match / 9 to match | Science | Pick the match | 9 | 2026.10.03 |
| 03 | What comes next? 20 number sequences 2, 4, 8, 16, 32 and then? Twenty number sequences, five terms each. Spot the rule and type the sixth term. Science / Type them all / 20 answers | Science | Type them all | 20 | 2026.10.03 |