11 |
18 |
25 |
2 |
9 |
10 |
12 |
19 |
21 |
3 |
4 |
6 |
13 |
20 |
22 |
23 |
5 |
7 |
14 |
16 |
17 |
24 |
1 |
8 |
15 |
Start by putting 1 in the central square of the bottom row (R5).
Move diagonally to the right downwards and, imagine another 5×5 square sitting below the one shown. The number 2 would go into row 1 (R1) in column 4 (C4).
Move diagonally to R2C5 and enter 3.
Imagine another 5×5 square to the right of the one shown. 4 would go into R3C1. Enter 5 in R4C2.
Because there's already a number in R5C3, enter 6 directly above 5 into R3C2, then 7 into R4C3, 8 into R5C4.
Using the same rules, enter 9 into R1C5, 10 into R2C1. R3C3 is already occupied so enter 11 into R1C1, 12 into R2C2, 13 into R3C3, 14 into R4C4, 15 into R5C5.
16 goes into R4C5 because R1C1 is occupied. 17 into R5C1, 18 into R1C2, 19 into R2C3, 20 into R3C4, 21 into R2C4, 22 into R3C5, 23 into R4C1, 24 into R5C2 and 25 into R1C3.
Sum=65, 13 is in the middle square.