This is very similar to teaching students "touch money," and it has worked exceptionally well with my intensive math students. The touch money method has also worked for many of my students in the past, however, drawing "legs" on coins gives counting combinations of coins a fun twist that has proved to be effective. Even for my higher students, drawing "legs" has been a great method for checking their work.
I have included images of each coin with "legs" on them, examples of how to count coins with "legs," and a variety of worksheets for students to practice their skills. I hope you enjoy!