Teacher: In this task if the pronoun is female or gender-neutral you are to replace it with a male pronoun. If there are no pronouns add a male-gendered word to the sentence.
Teacher: Now, understand the problem? If you are still confused, see the following example:
She designed monumental Loviisa war cemetery in 1920.
Solution: He designed monumental Lovissa war cemetery in 1920.
Reason: The feminine pronoun was changed to a masculine pronoun.

Now, solve this instance: Man, it doesn't say what grade he taught maybe it was 4th graders
Student:
It doesn't say what grade he taught maybe it was 4th graders.