It's an okay game, but I'm not really a fan of the puzzles this time around. Math as three separate puzzles is such a pain. It's also kinda short and it's not nearly as interactive of an environment as your other games...
~Spoilers for the first math puzzle~
Start on the bottom left of the boxes, and look at the number above. Subtract the number above from the number below (4-2) to get the number that goes in the box to the right. Do the same for the triangle above (8-4) to fill in the number above the answer to the first equation, which tells you what the third number on the bottom row is. That should be enough for you to understand the basics; just work in triangles, using what you have to fill in the missing numbers on triangles above and below, until you reach the answer on the walkthroughs that are confusing everyone.