Question 668192
Another way of thinking about 12 1/2 is that it is (12 + 1/2). What is 1/2 in decimal form? What does it mean to be in decimal form? That means that we are in terms of 10.  So what is 1/2 in terms of 10? It is 5/10. So  1/2 = .5.

Then we have that 12 1/2 =  12.5