Notice the blue row of numbers at the bottom ("8", "9", "6", "7", "8"). Your challenge is to transform those numbers into 424 (in green at the top). Also notice that only the row of blocks at the base of the pyramid are enabled. This is where you start. In this case we choose the block straddling the numbers "9" and "6". We will perform an operation on these 2 numbers and the result will be placed in the block. The rest of the row will then be filled with the other numbers these blocks are sitting on. When you choose a block, notice that it is highlighted with a green line.
Now you choose the operation you will perform, "9+6", "9-6", or "9x6". The correct answer is "9x6", so you click "X".
You can see that the result, "9x6=54" is displayed at the bottom of the screen, the result (54) is placed in our block, and the other numbers bubbled up to fill the vacant blocks in the row. This is the only operation we can perform on that row, so now we work on the row of blocks that rests on the row we just filled in.
In this case, the rightmost block is chosen to be the difference of the blocks on which it rests.
For the next row we add "54 + -1" in the right-most block to yield 53.
Finally, multiply the 2 remaining numbers to solve the puzzle. In the full version of the game (only 99 cents), you would see that you achieved the third highest score. You can see your score at the bottom of the game. Your score is based on how long it takes you to solve the problem and the complexity of the puzzle (the complexity only changes in the full version).
You will find that solving these puzzles can be quite challenging. You can "Undo" your choices at any time. If you need help, ou can use the "Hint" button to get you on the right track. The first time you click "Hint" you are shown the correct block at the bottom of the pyramid. The next time you click "Hint" you are shown the correct operation to perform on that block, etc.
You will not be allowed to use "Hint" on the last few blocks. Each time you ask for a hint your score is reduced. Note that some puzzles will have more than one solution. The hints that are provided are for one of the correct solutions.
I recommend that you use "Hint" repeatedly to get a feel for how the game works the first time you play.
You can slide open the "drawer" at the bottom of the game at any time to see the rules and the high scores.
Full Version vs Regular Version
The full version of the game has only a few capabilities that the basic version doesn't, but the cost reflects that. Firstly, you get a list of the top high scores.
You also get the capability to make pyramids of different sizes and control which operators are used in the puzzles. If the game becomes popular enough (unlikely since it's so nerdy :)), I will enhance the full version with more features. For example, originally I played with using "mod" as an operator but thought that was a bit much for most people to appreciate.