These Permanent Record achievements are level up achievements based on the amount of points you get across games.
The best way to grind experience is to play Study Mode with 8 players in single controller mode. Then, you just need to get every answer correct. Feel free to google, use a calculator, or use the built in cheats to get the correct answer.
For 5th Grade on the Permanent Record, you'll need to get up to the late 100ks