I’m offering a rough suggested range of grade 3 through grade 6 for this, but it depends on your child’s math abilities and interest in “running a business”. A calculator may help if percents and decimals are not familiar. There are also daily calculations involving addition, subtraction, multiplication, as well as working with demicals in terms of money.
While I tried to keep this as broadly themed as I could, it does have some Wiccan leanings with several references to covens and pentacles. I think that it should still be creative and relevant no matter what your specific path.
An answer key is included, providing totals for each day’s transactions.