Bubbles can be popped when they are touching the row of small white dots at the top of the fish tank. You can pop bubbles by placing tiles in front of iPad such that their total matches the number inside the bubble. Remember, the bigger the number inside the bubble, the more water it adds to the tank when it pops.
The way that Osmo interprets your tiles depends on which mode you are playing. In “Count” and “Add” mode, all the tiles visible to Osmo will simply be added up to form the total. In “Connect” and “Multiply” modes, tiles that are close to one another take on a special meaning. In “Connect” mode, they are joined together to form a bigger number. For example, a 3-tile and a 6-tile placed next to each other will be interpreted as 36. In “Multiply” mode, the same tiles would be multiplied, forming 18. Any tiles that are placed away from a group of closely placed tiles will be added, just like in “Count” or “Add” modes. Continuing the example above, a 2-tile placed away from the 3- and 6-tiles would bring the total up to 38 for “Connect” mode and 20 for “Multiply” mode. Remember, you can have more than 2-tiles forming a close group, too. Also, you can have several close groups and several “away” tiles in a single move for maximum flexibility in forming totals.