Fundamental coding help

I feel more accomplished with this than with #4, but aside from sorting out all the special cases one by one, I can't think of another approach. Any suggestions/evaluations? I don't mean to be studying things I'm not supposed to. I'm just thinking there might be a fundamental technique that I missed from reading the guides.

Also, is it noticeably bad practice to create unnecessary objects? Like the remainder below with is only used once and can easily be substituted by goal%5?

 Spoiler

[COLOR="red"]We want make a package of goal kilos of chocolate. We have small bars (1 kilo each) and big bars (5 kilos each). Return the number of small bars to use, assuming we always use big bars before small bars. Return -1 if it can't be done.

makeChocolate(4, 1, 9) → 4
makeChocolate(4, 1, 10) → -1
makeChocolate(4, 1, 7) → 2[/COLOR]

Code:

public int makeChocolate(int small, int big, int goal) {
int remainder = goal%5;
int totalSum = small*1+big*5;
int miniSum = goal-(goal%5)+small;

if(totalSum<goal) {
    return -1;
}
else {
    if((big*5>goal) && (miniSum<goal)) {
       return -1;
    }
}
    
if(big<goal/5) {
    return (goal - big*5);
}
else {
    return remainder;
}
}