Daniel bought a pokemon card at a store for $10. He sold the card for $20.
Later he bought the same card back for $30 and then sold it again for $50.
How much money did he make or lose on the pokemon card?
if you minus 10 from zero you get -10 and then add 20 which gets you 10 dollars. Minus 30 from the ten and you have -20. add 50 to that and you have 30 dollars.
