Play it · Ages 15–16
Count the Infinite
Build the number that is not on the list. Three challenges — each one changes what you have to do, not just how many of it there are. Nothing is timed and nothing is scored.
0 of 3 solved
Build a number that differs from every row on the list.
Change the digit on the diagonal. Row one's first digit, row two's second, and so on.
Four rows
| 1 | 0.1428571… | |
| 2 | 0.3333333… | |
| 3 | 0.6180339… | |
| 4 | 0.7071067… |
0.____
Ten minutes of stuck counts as the work.
Now do it away from the screen
The board is the warm-up. The year page has the same problem on paper, the hint ladder, the answer, the five-day week and three questions nobody can mark — which is where the twenty-five minutes actually go.