Jerome has a penny, a nickel, a dime and a quarter. how many different two-coin sums can he make?

So you have 1 of each a penny a nickel a dime and a quarter so the number combos is shown below
1   penny and nickel
2   penny and dime
3  penny and quarter
4  nickel and dime 
5  nickel and quarter
6  dime and quarter

The reason why number 4 doesn't say nickel and penny is because is if I had said that it would of been the same as number 1 just that the penny and nickel has switched places so the number of different 2 coin sums are 6

also a penny + a nickel + a dime + a quarter is = to 41 cents 

What am i doing here. add?