AI Tutor
Imagine you want to buy a juicy red apple that costs 1,butyouonlyhavea1, but you only have a 5 bill in your pocket.
Can you still buy the apple even if you do not have a single one-dollar bill?

Paying with More

Yes! Understanding greater value means that if you do not have exact coins, you can pay with a larger note or coin where Amount Paid>Cost\text{Amount Paid} > \text{Cost}.
Since you gave the cashier more money than the apple costs, what happens to the extra dollars?

Getting Change Back

The cashier keeps the cost of the apple and returns the unspent money to you as change (Change=Amount Paid−Cost\text{Change} = \text{Amount Paid} - \text{Cost}).
This shows a part-whole relationship: the Amount Paid is the whole, while the cost and your change are the two parts (extCost+extChange=extAmountPaid ext{Cost} + ext{Change} = ext{Amount Paid}).

The Part-Whole Relationship

We can see money as a part-whole relationship: the Amount Paid is the Whole, while the Cost and the Change are the two parts (Cost+Change=Amount Paid\text{Cost} + \text{Change} = \text{Amount Paid}).
Do you always get change every time you buy something?