Transformers: Revenge of the Fallen

When going for this achievement you will get Do the Math before because it takes more then 2 million energon to purchase all the Autobot upgrades.

It takes about 2.8 million energon, and when I beat the Autobot Campaign for the first time I finished with 1.6 million energon. So it shouldn't take much longer to get enough to buy all the upgrades. Once you complete the Autobot Campaign, just keep playing the last level over and over again until you get this achievement. The last level will give you 200,000 energon just for beating the level, so any bonuses (like all skill shots) you earn will be added to that. Don't worry about the credits, you are only forced to watch them once. So the next time you beat the last level you will be immediately returned to the upgrade screen.

The best method for this achievement is to work on it throughout the campaign and just keep building toward it while you try and earn Platinum on every mission, however you may find you still need this achievement after doing that or you might find you're struggling to earn Platinum on a few levels, if that's the case then you should head over to; Cairo Pyramids - Rise Of The Fallen.

Once you've gotten used to the level and what you need to do to finish it you should be able to finish this level in about 3 minutes, which not only will net you the Platinum medal for this level but for defeating The Fallen you'll net yourself 200,000 Energon which is what is used as currency in this game.

To purchase upgrades you need to use the LT/RT buttons to switch through the menus while in the Autobot campaign, it's not hard to find, in fact after completing a mission it normally automatically takes you to that menu screen!

Using this method you'll rack up Energon in no time and unlock this achievement with ease, now while I don't know the exact amount needed to unlock all the upgrades I estimate it to be around the 2 million mark, after unlocking this achievement I unlocked Solution for Do the Math In Transformers: Revenge of the Fallen within 1 more run through on Rise Of The Fallen!

I've linked in a video of someone playing/completing the last mission (named above), if you find yourself stuck on it or confused about what to do, use it as a reference!

* ^{Credit to captainxena for the video}