I can offer some real life situations for you to consider some may depend on how much access you have to them.
It is the holiday season and many sales are in progress, that means mark downs, discounts, clearances all versus retail prices. Do you or someone you know have a holiday spending budget?
It is the end of the year many people will getting ready to do their taxes. Do you or someone you know work? Do you know your Gross Income, Annual Deductions, Contributions, if you will owe money, or get a refund?
It is the end of the semester for most students, tests, homework, class work probably contribute in some large mathematical fashion to their final grade.
Sale prices are usually some percent of retail price, the amount of your regular set of deductions per pay period can be handled as a percent of your gross income that leaves you with a net income and finally, tests, homework, and maybe attendance tend to contribute to overall grades on a percent basis.
