Subtracting fractions

Question

Leo cut 2 3/ 4 inches from the width of an 8 1/ 2 -inch-wide piece of paper. How wide is Leo’s paper after cutting it? I get that I have to give the problem common denominators, but where I'm confused about is how in the book they went from 8 2/4 to 7 6/4.

Answer 1

8 2/4

Because 1 = 4/4, we are borrowing 4/4 from 8, thus making it 7 and adding the 4/4 to the 2/4.

8 1/2 - 2 3/4 = 8 2/4 - 2 3/4 = 7 6/4 - 2 3/4 = 5 3/4