Note- If you have the time, scroll down this extensive list of links
to see what is available to print or do online for free, or for future planning.

Many websites overlap categories so if you want to find something specific,
press "control" and the letter "f" on your keyboard, then type a "keyword"
in the box that appears. Click on "find" and you will go to the first occurance
of the word on the page. Repeat until you get to the bottom of the page.

Search Tips- Less words give better results than lots of words.
"Graph" gets more hits than "graphs" or "graphing."