Explain the difference between saving and spending money, and identify a trade-off between the two choices.
Every time you get money, you have a choice: spend it now on something you want, or save it for later. Spending gets you something right away. Saving means waiting, but it can let you buy something bigger later.
This choice is called a trade-off: you cannot spend the same dollar AND save it. Choosing one usually means giving up the other, at least for that dollar.
Mastery looks like: They can explain the difference between saving and spending and identify what is given up (the trade-off) in a real choice.
Common stumbles: Thinking saved money "disappears" or does not still belong to them, or not understanding that spending and saving the same dollar cannot both happen.