Question

Assume that price is an integer variable whose value is the price (in US currency) in cents of an item. Assuming the item is paid for with a minimum amount of change and just single dollars, write an expression for the amount of change (in cents) that would have to be paid.

Answer 1

`Change = (Paid*100) - Price`

Explanation:

First of all we need to know the relation between 1 dollar and 1 cent in order to express everything in the units required in the question.

We know that
`1 dollar = 100 cents`, so the amount paid for the item with single dollars has to be multiplied by 100 to express its value in cents.

`Paid_(cents)=Paid_(dollars)*100`

Now that we have everything in cents, we can make the subtraction:

`Change_(cents) = Paid_(cents) -Price_(cents)`

Replacing the value in cents we get:

`Change = (Paid*100) - Price`