A border collie needs to get across a floor of numbered tiles, and only some of them are strong enough to hold her. The rule is at the top of the screen: "Multiples of 3" means 12 and 27 are safe to stand on, and 13 is not. Step onto a tile that does not fit and it cracks, she drops through, and she has to start again from the beginning.
Every floor has a safe way across, so a player who knows the multiples can always make it. Broken tiles stay broken, and tiles she has already crossed keep a paw print, so a fall is never wasted: it shows exactly which number was wrong, and the game explains why. Cross without falling for three stars.
Each floor brings a new rule. There are multiples of 3, 4, 6 and up; "Makes 24" floors where the tiles are times table facts like 3 × 8 and 4 × 6; and factors floors that ask which numbers divide into 24 or 36. Move with the arrow keys, or tap a tile next to her on a phone or tablet.
Use the arrow keys, or tap a tile next to the dog, to move one tile at a time from the start ledge to the other side. Only step on tiles that fit the rule shown above the floor. A tile that does not fit breaks, and the dog falls back to the start.
Yes. Every floor is built with a safe path of tiles that fit the rule, running from the start to the far side. There may be other safe tiles that lead to dead ends, so it pays to look ahead before stepping.
The game explains why the tile was wrong, for example that 22 is not a multiple of 3 because 3 × 7 = 21 and 3 × 8 = 24. The dog goes back to the start, but the broken tile stays broken and safe tiles keep their paw prints, so the next attempt starts with more information.
No. There are no lives and no game over; a fall only costs the walk back. Each crossing earns up to three stars: three for no falls, two for one or two falls, and one for making it across at all.