4 campers went rowing and 36 campers went hiking in the morning. 46 campers went rowing in the afternoon. How many campers went rowing and hiking in all?
How many campers went rowing in the morning? 
4 
How many campers went hiking in the morning? 
36 
How many campers went rowing in the afternoon? 
46 
How many campers went rowing in all? 
4 + 46 = 50 
How many campers went hiking in all? 
36 
How many campers went rowing and hiking in all? 
50 + 36 = 86