In Lesson of Peanut, what is the purpose of the mother letting her children grow peanuts in the wasteland?

At the moment of peanuts, what is the purpose of the mother to let the children open up wasteland to grow peanuts? I think at this moment, my mother let her children plant peanuts in order to save some money for their children to go to school. It costs children a lot of money to go to school. Let the children open their own houses to grow peanuts, so that the peanuts they grow can be sold, and the children can go to school with the money from selling peanuts. I think that's what it means. Children will be thrifty when they grow peanuts, and frugal when they go to school.