Code:
 #include <iostream>
#include <vector>

using namespace std;

class GradeBook {
    
public:
    double getGrades()
    {
        
        double total=0.0;
        int amount;
        
        cout<<"Enter the amount of grades you need to enter"<<endl;
        cin>>amount;
        cout<< "Enter the students Grades: "<<endl;
        
            for (int i =0; i < amount; ++i) {
                
                vector<int> grades(amount);
                cin>>grades[i];
                
                total += grades[i];
            }
            averageGrades(total, amount);
        
        return total;
    }
    
    double averageGrades(double total , int num)
    {
        
        double average = 0.0;
        
        average = total / num;
        
        return average;
    }
    
    void letterGrade()
    {
        double grade=0.0;
        int number=0;
        
        cout<<averageGrades(grade, number)<<endl; // test to see if values are being passed
    }
    
private:
    
    
};

int main(int argc, const char * argv[])
{
    GradeBook GradeTracker;
    
    GradeTracker.getGrades();
    
    GradeTracker.letterGrade();  // this is returning "nan"
    
    return 0;
}
I changed it up a little. I am just testing at this point to see is my values are being passed correctly and they are not. What am I doing wrong?