Danny has 13 bottle caps in his collection. He found some more bottle caps at the park. If he has 35 bottle caps now How many bottle caps did he find at the park?
Danny has 13 bottle caps in his collection. 
He found some more bottle caps at the park. 

We want to know how many bottle caps he found at the park. 

We can set up an equation to solve this problem: 

13 + x = 35

We want to know what x is equal to. 

We can solve this equation by subtracting 13 from each side: 

13 + x = 35
-13 -13
0 + x = 22

We can see that x is equal to 22. 

Danny found 22 bottle caps at the park.