Let's start with #1. You divide [0,1] into 10 equal sub-intervals [0,0.1],[0.1,0.2], ... ,[0.9,1]. Then you estimate the area under the curve from 0 to 0.1 (for example) by a rectangle with width 0.1 and height f(0.05) - this is the midpoint rule (0.05 is the midpoint of [0,0.1]). So you add up the areas from all 10 sub-intervals and that's the estimate of your integral.

If you show me your work, I could check it for you.

Numbers 2, 3, and 6 are similar, just with different methods of finding the height of the rectangles.

- Hollywood