American coins.
1, 5, 10, 25
English coins.
1, 2, 5, 10, 20, 50
I think our coin system is better. You can use less of it to make up an odd amount of change. Let's take 99p or 99 cents.
25 25 25 10 5 5 1 1 1 1 are all needed to make 99 cents.
50 20 20 5 2 2 are needed to make 99p.