Get percent of failing grades from an array

Hello everyone! I was working on a problem that I thought would be quite simple, but for some reason, my code won't return any percentage other than 0. I am supposed to return the percentage of grades that are less than 60 from an array of grades. This is what I came up with:

Code java:

---

public class FunctionalityTest
{
    public float getPercentFailing(float[] grades)
    {
        int failed = 0;
        for (int i = 0; i < grades.length; i++)
        {
            if (grades[i] < 60f) 
            {
                failed += 1;
            }
        }
        return failed / grades.length;
    }
}

---

Any help or advice would be very much appreciated!

Integer arithmetic: 9/10 = 0
float arithmetic: 9.0/10 = 0.9

Make one of the numbers a float to get float arithmetic