Our most recent science unit began with my son wanting to figure out how zip lines worked, so I figured that it would be a good way to tackle simple machines. So we started with pulleys and got through it pretty quickly. Then mommy took a nice spring break before starting to learn the other machines.
And yes, mommy did have to read up and relearn all sorts of great stuff. In fact, that's a hidden bonus to homeschooling--relearning stuff that you forget a long time ago. Did you know that there are 6 simple machines? Or that a zip line is a movable pulley? I didn't until a couple of weeks ago. That information was long filed away in the no longer pertinent file. Now the trick is to see how long we can both retain this stuff :p
K...editing this post to say that i got smart and figured out how to combine the printouts into two files and I found a better way to share files. The first file has the worksheets and the other one has all the answer keys and you can get the links in this post