How can you subtract 45 from 22?

Question

The answer is more like 22 from 45. In such a case do you always make it a negative number? 

Answer 1

Adding a negative number is the same as subtracting a positive number:

 

22 + (-45) = 22 - 45 = -23

 

Another way to think of it is to factor out a -1:

 

22 - 45 = -1*(45 - 22) = -1(23) = -23

 

A third way to think of it:

 

45 = 22 + 23, so

 

22 - 45 = 22 - (22+23) = (22-22)-23 = 0-23 = -23