Tom spends $250 to buy gems in a game he plays.  The game gives 100 gems for each dollar you spend.  Since he bought so many gems he got a 20% bonus of more gems. How many gems did he end up with?
He bought 250*100=<T>multiply(250, 100)=25000 gems
He got a 25,000*.2=<T>multiply(25000, 0.2)=5000.0 gem bonus
So he got a total of 25000+5000=<T>add(25000, 5000)=30000 gems
,000