Danny collects bottle caps and wrappers. He found 10 bottle caps and 9 wrappers at the park. Now he has 42 bottle caps and 2 wrappers in his collection. How many bottle caps did danny have at first?
Danny found 10 bottle caps and 9 wrappers at the park. 
That means he had 10 + 42 = 52 bottle caps and 9 + 2 = 11 wrappers in total. 
Now he has 42 bottle caps and 2 wrappers in his collection, which means he gave away 10 bottle caps and 9 wrappers. 
Therefore, he had 52 - 10 = 42 bottle caps and 11 - 9 = 2 wrappers at first.