01
Inspect the two turns as well as the straight runs
Within the first row, the route makes three rightward moves. Cell 4 sits directly above cell 5, so the next move is downward at the right edge. The second row then makes three leftward moves, ending at cell 8. Cell 9 is directly beneath it at the left edge. Three final rightward moves finish at cell 12. Every consecutive pair shares a side. There are eleven transitions for twelve visited cells, and each cell appears once in this supplied route. No diagonal or return to a previously visited cell is required.
02
Compare the row reset under the same movement rule
If all three rows were numbered left to right, the transition from 4 to 5 would jump from the rightmost cell of the first row to the leftmost cell of the second. Those cells do not share a side. The same issue occurs from 8 to 9. That conventional reading order is perfectly usable for many documents, but it does not satisfy this exercise when each consecutive number must be a side-adjacent move. The comparison is about a stated rule, not a claim that winding layouts are always easier to read or better for every application.
03
Record the route before applying a visual treatment
The reusable route sheet records row count, column count, starting cell, first-row direction, reversal rule and permitted adjacency. Add the numbered grid and check each boundary transition explicitly. If the design becomes a card activity, keep the numbers visible after decoration. If it becomes a display plan, treat physical dimensions and access as separate design work. Preserve the plain grid as the reference version so an altered colour or line treatment can be checked against the same intended order. The worksheet establishes sequence, not suitability for a real venue.