Firstly you need to to reduce to a common denominator by multiplYing the whole fraction. This way you have to multiply 4/5 by 2 (both numerator and denominator). so 4/5 = 8/10. And now you have 8/10 and 9/10. You compare only numerators. This way you have 8/10 <9/10. Same goes for 2/3 and 5/8. Only here you need to multiply both fractions. The common denominator here is 24. So you have to multiply 2/3 by 8 and 5/8 by 3. You now have to compare 16/24 and 15/24. 16/24>15/24.