java problem

I am not getting this, "i remainder 10 == 0"
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What are the values of i and sum after this code is executed?

    int sum = 0;
    int i = 0;

    for (i=0; i<40; i++)
    {
        if ( i % 10 == 0)
            sum += i;
    }
    System.out.println (“The sum is  “ + sum);