Each train pulls five cars with one coin in each, already ordered from biggest to smallest. The child starts with the first coin and counts on, writing the new total in the box under every car. A worked example at the top shows exactly how it goes: 25¢, 35¢, 40¢, 41¢.
This is the method most teachers want children using for every coin problem, and the train makes the running total visible instead of something held in the head. Train 4 has three quarters in a row, a nice moment to practice counting by 25s. Once a child is comfortable here, coins that arrive in a jumble feel much less daunting.