Advent calendar 2017
9 December
Write the numbers 1 to 15 in a row. Underneath, write the same list without the first and last numbers. Continue this until you have just one number left.
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 |
| 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | ||
| 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | ||||
| etc. | ||||||||||||||
Today's number is the sum of all the numbers you have written.