He grates 6/8 pounds of cheese in all.
For this problem, you just have to add the numerators and keep the denominators.
4/8 + 2/8 = 6/8.
Remember, if the denominator is the same, just add the numerator.
When you add fractions remember only add the numerator. There has to be a common denominator. Like 8.
4/8 + 2/8
4+2=6
So the answer is 6/8