Answer:
Equation:356+365+x= 977
Solution: 256 Kids in 9th grade.
Step-by-step explanation:
Since there are 977 kids in total, you have to add 356 and 365 to get 721.
Then you subtract 721 from 977 to get how many kids are in 9th grade.
Therefore, there are 256 kids in the 9th grade.