A、Because they have to choose between spending and saving for future use. B、Because they will soon spend all the money. C、Becaus

Many children first learn the value of money by receiving an allowance.(7)The purpose is to let children learn from experience at an age when financial mistakes are not very costly.
    The amount of money that parents give to their children to spend as they wish differs from family to family. Timing is another consideration. Some children get a weekly allowance. Others get a monthly allowance. At first, young children may spend all of their allowance soon after they receive it. If they do this, they will learn the hard way that spending must be done within a budget. Parents are usually advised not to offer more money until the next allowance. (8)The object is to show young people that a budget demands choices between spending and saving. Older children may be responsible enough to save money for larger costs, like clothing or electronics. Allowances give children a chance to experience the things they can do with the money. They can share it in the form of gifts or giving to a good cause.(9)They can spend it by buying things they want. Or they can save and maybe even invest it. Saving helps children understand that costly goals require sacrifice: you have to cut cost and plan for the future.
    Requiring children to save part of their allowance can also open the door to future saving and investing. Many banks offer services to help children and teenagers learn about personal finance.