Sheldon correctly pronounces the word 'data' with a long "a" in the first syllable (i.e. DAY-tuh). On The Big Bang Theory (2007), adult Sheldon habitually pronounces the word with a short "a" in the first syllable.
Mary, while worried about Meemaw's gambling addiction, mentions that an Italian person would be taking her truck for unpaid debts. Meemaw drives a Cadillac, as shown in Poker, Faith and Eggs (2017).
Sheldon says he got B+ because he forgot to show his work but his answer is actually wrong:
The correct answer is y = -2/3x + 2, with a minus sign.
Moreover, his plot is wrong: the point (1;-4) is drawn at (1;-6).
It's possible the teacher missed those errors, but it's dubious Sheldon made them.
In the last scene, Meemaw is playing slots in a casino in Louisiana. The show takes place in 1989. Casino gambling did not become legal in Louisiana until 1991.