Description: Sal subtracts 3/4 - 5/8 using a fraction model for help. You could view this entire bar as a whole, and we see that it is divided into four equal sections, and that three of them are shaded in. This is another whole right over here and you could see this divided into eight equal pieces, and five of them are shaded in. Whenever we add or subtract fractions, we like to think in terms of having the same denominator.*Teacher Advisor is 100% free.