Paul got a box of 43 crayons and 45 erasers for his birthday. At the end of the school year he only had 22 left while not having lost a single erasers. How many crayons had been lost or given away?
1. Paul got 43 crayons and 45 erasers. 
2. At the end of the school year, he had 22 crayons left. 

That means that 21 crayons were lost or given away.