Here is the full list of all 30 Are You Smarter Than a 5th Grader? Game Time achievements worth 1,000 gamerscore.
$50,000,000 total winnings
Correctly answer one question from all categories
Answer 6,000 questions correctly
Correctly answer 100 History questions (all variations)
Earn a total of 25 points across all Extra Credit games played
Complete 12th grade
$1,000,000 in Showdown math games
$25 million total winnings on Xbox LIVE
$25,000,000 total winnings
Win 50 Xbox LIVE games (combined)
Win 25 Xbox LIVE games (combined)
Answer 1,000 questions correctly
$10 million total winnings on Xbox LIVE
Play 100 complete games (combined)
Correctly answer 100 Science questions (all variations)
$10,000,000 total winnings
$5 million total winnings on Xbox LIVE
$5,000,000 total winnings
Correctly answer 50 questions in a row (Xbox LIVE only)
$1,000,000 in Showdown spelling games
Win one game in each mode over Xbox LIVE
Correctly answer 25 questions in a row (Xbox LIVE only)
Win one Xbox LIVE game (any non-Homeroom mode)
Correctly answer 15 questions in a row (Xbox LIVE only)
Win an Xbox LIVE match consisting of 4 players (any mode)
$1 million total winnings on Xbox LIVE
Win $1,000,000 in Homeroom (Xbox LIVE only)
Correctly answer 5 questions in a row (Xbox LIVE only)
Play a perfect game in Homeroom (Win $1 Million with an A+ and no cheats)
Win $1,000,000 in Homeroom mode (local game only)