what have you got so far?
This should be straight forward.
1. declare an integer variable
2. use std::cout to display some text asking the user for a value ( between 1 and 10 inclusive).
3. use std::cin to get the user value into the variable
4. check value entered is valid, if valid - then use new function to create an array of the specified size to hold the grade values.
if the value entered was not valid - then use std::cout to display an error message to the user and possibly exit the program
5. Assuming, we got a valid response from the use in step 4 above - then use
a for loop based on that value , and ask the user to enter a value for each grade in turn
Start with that..... we'll expand on step 5 when you get that far.