Merge Numbers

There are no written instructions, just a demo that states “Tap a number. Merge to bigger”. I do not find that very informative. Eventually I figured out that only a block adjacent to a block with the same number can be tapped at which point the number tapped increases by one and the adjacent block with that number disappears. If multiple blocks with the same number are adjacent to each other, the number tapped still increases by just one even though all of the adjacent blocks with the matching number are eliminated.