I founded The Homework Club, a California Non-Profit (501 © 3) from 1997-2014. This was an after school program at Middle Schools in the San Francisco Bay Area. We focused on struggling students, no just economically but in mathematics mainly.
The program was the first of its kind to help parents work better with their children, designing an email system that kept them informed daily of their child's progress and what was still to be finished at home. Remember this nonprofit started at the beginning of email.
Not having the appropriate materials to teach kids with math anxiety we set out of create worksheets on about 80% of what our students needed to succeed in algebra.
The Free Resource (Math Study Skills) was written as a training guide for new tutors. I believe parents at this period in our US history need a bit of help with teaching their own kids at home.