Body and Brain Connection

For this method, you'll need to have your controller in your hand for it to work. Also, you'll need to complete an exercise on Intermediate difficulty to unlock its Advanced difficulty. To get this achievement easily, just go into Math from the Custom Exercises screen and select Which is Bigger. Now you'll have to select Advanced difficulty. Once you're in the game, press the guide button on your controller to pause the game. You'll be able to solve the equations and put your hands in position while in the guide. Once you're in the correct position for the correct answer, press the guide button again to resume. If you do this for each question, you should get at least 19/20 correct with a good average time which will net you an easy "A" and an achievement. You can also do this for many other games such as Math Jock since this method works with legs, too. If you've given me a negative vote, please explain why. Also, please don't just give it a negative vote because it's cheating.

If you want to get this achievement without pausing the game with the guide button:

I personally found the easiest level to be the Advanced Flag Frenzy level, I got 33/35 correct with an avg time of 0.93 and got an A.