Drawing upside down

One of the objectives of the illustration course I took on svslearn.com was to know where my weak areas are.  I discovered I had more holes in my drawing abilities than I thought.  So the class I'm taking this month is How to Draw Everything, covering the basics of drawing anything.

The first assignment is 1 of 3 drawing exercises given:  drawing upside down.  It's as simple as it can get, yet one of the most challenging thing's I've done!  I did notice that everything I tend to draw upside down is larger than the object I'm comparing it to. . . . food for thought as I practice.  There's only 1 assigned in the class, but as I've got endless material at my fingertips (my children's bookshelves are being raided), I'm going to do 10.

The first one is from a board book call Are You a Cow? by Sandra Boynton.

The second is from If you Give a Mouse a Cookie by Laura Joffe Numeroff.