So first you want a common denominator so we have to find the least common multiple of 3 and 8, which is 24.
Next you have to multiply the same to the numerator, I usually go by the phrase whatever you do to the bottom you do to the top. So 8 times 2 is 16 and 3 times 3 is nine.
Everything changed should be 16/24-9/24
then we do 16-9 is 7 and you never subtract the denominators so 2/3-3/8 is 7/24
