Dan has $ 8. He bought a chocolate for $ 39 and a candy bar for $ 2. How much money did he spend to buy chocolate than he did to buy candy bar?
Dan has $8. 
He buys a chocolate for $3. 
This leaves him with $5. 
He buys a candy bar for $2. 
This leaves him with $3. 

So, he spent $1 more on the chocolate than he did on the candy bar.