Q: How much is 90 minus 21? A: 
Q: How much is 48 minus 44? A: 
Q: How much is 95 minus 21? A: 
Q: How much is 90 minus 20? A: 
Q: How much is 60 minus 21? A: 
Q: How much is 90 minus 81? A: 
Q: How much is 99 minus 20? A: 
Q: How much is 90 minus 21? A: 