You see a pair of shoes that you really want. They are priced $97.00 (Tax included)
But you don't have any money so you borrow $50.00 from your mother and $50.00 from your dad = $100.00
You buy the shoes and you still have $3.00 left.
So you give your mom $1.00 and your dad $1.00 and keep $1.00 for yourself.
Now you owe your mom $49.00 and your dad $49.00
49+49= $98.00 Add the one you kept and you get $99.00
Where is the other $1.00?????