Jim buys a wedding ring for $10,000.  He gets his wife a ring that is twice that much and sells the first one for half its value.  How much is he out of pocket?
The second ring cost 2*10000=$<T>multiply(2, 10000)=20000
He sells the first ring for 10,000/2=$<T>divide(10000, 2)=5000.0
So he is out of pocket 10000-5000=$<T>subtract(10000, 5000)=5000
So that means he is out of pocket 20,000+5000=$<T>add(20000, 5000)=25000
