Obviously home works help cause in one sentence we can say that "Practice makes everything perfect." Your teacher can only show you the ways to solve questions, even he/she can solve it once or twice for you but if you don't get home work or you don't do then you will forget. Home work also help to solve one problem in different way. Suppose 3 upon 3 = 9. That 3 multiply with 3 which will bring the result 9. Again in another way 3 upon 3 mean you add 3 up to 3 times and result will be 9.(3+3+3 = 9). This way and through many other ways home work helps.

Sum Problems answer:

1/2, 1/4, 1/8 all these mean that these are part a whole one.
Suppose 1/4: You take 1 page. Cut it in to 4 pieces and take 1 from those 4 pieces and that is the 1/4 part of that page.

This way 1/4, 1/8/, 1/16 or 1/whatever the number is those all are smaller than 1 but part of 1. Here you are just breaking the 1 into fractions and want to do the sum which can never lead the result to be grater than 1. The sum will get infinitely closer to 1 but not gonna be grater than 1.