What is happening here?
Calculating with money connects numbers to a real object. At the same time it is demanding: coins do not have an intuitive number value (a small 2-euro coin is worth more than a big 1-euro coin), and figuring out change already calls for flexible adding and subtracting.
What helps at home
Let your child help out on your next shopping trip: how much do two items cost together? Do we have enough money? How much change do we get back? Holding real coins in their hands makes a big difference compared to printed pictures in the workbook.
Play shop. Let your child take turns being the cashier and the customer. Working out the change is the trickiest, but also the most instructive task.
What can go wrong
Some children count every cent one by one, even when bigger coins would be easier. Show them how to first add up the big coins and then add the small ones. That trains structured calculating.