Jo asks:
Can you explain the “filing cabinet on the web” a little more? Is this a place a teacher can print copies for the class or does each student have to have subscription?

Dr. Don answers:
A subscription gives you access to our “filing cabinet on the web.” This is a place on the web where we keep all the worksheets and a teacher goes there to print out what is needed. You just click on what you want and print it out. Each operation has its own drawer. Each drawer looks like this:

There are five drawers that can be accessed with the $29 basic subscription: Forms and Information, Addition, Subtraction, Multiplication, Division.

But wait there’s more!
There are currently 8 more drawers, the contents of which are only available to those who have the $49 Universal subscription. The 8 programs added in the Universal Subscription are: Rocket Writing for Numerals, Skip Counting, Add to 20, Subtract from 20, Multiplication 10s, 11s, and 12s, Division 10s, 11s, and 12s, Factors, and Integers. Click on the name of any of these programs and you can get more information on that program.
You can preview (before you buy) the whole subscription site here: Rocket Math Subscription preview site.