Next Dollar Over is an essential money skill, particularly as students grow older. Never teach coin identification to anyone older than nine. Before then, it mainly a math thing, rather than a coin usage. Opportunities to use coins are becoming more rare. After the age of 10 what you want to teach about coins is: 1. Find a container and put all your coins in it. 2. When the container is full, have the bank give you real money for the coins and go buy something cool for yourself.
Here are some resources for teaching Dollar Over.
Next Dollar Up Strategy: Resources and Freebie
Of course, there's an app for that.