Very Minimal Calculator.
You can register simple addition and subtraction and leave it as a memo.
It is not necessary to be as powerful as household account books, but please use it if you want to record simple daily income and expenditure or to record childrens pocket money in a simple way.
Since you can manage multiple income and expenditure, the first one can be used for your husbands pocket money and the second one can be used for a childs bento substitute.
Of course, there are no limitations on the number of revenues and expenses that can be managed, so families with many children do not need to worry.