Let's talk about Math Mammoth. Math Mammoth is available at http://www.mathmammoth.com/. These are a series of inexpensive down loadable math workbooks for grades 3-8 and complete down loadable math curricula for grades 1-5. There are four series of these math e-books, written by Maria Miller, a math teacher. The series are Blue (math presented by TOPIC for grades 1-5), Light Blue (this is the complete set for grades 1-5), Golden (worksheets organized by grade for grades 3-8; not a complete text), and Green (worksheets for grades 3-8 organized by topic). Please note that there are no explanations in either the Green or Golden series, just problems.
The website goes into great detail about which item to use with your children. You can sign up to receive the Math Mammoth emails/newsletter and you'll get a bonus of 280 free worksheets and sample pages.
I got to download two products, the Golden series grade 7/pre-algebra set and the complete Light blue 3rd grade set. I really think these could be a very useful and cost-effective tool for homeschooling families. My only setback was I didn't have as long as I usually do the test the products extensively. Math texts are not something I want to skip around in so we began...where else? At the beginning, which is, as Maria sang in The Sound of Music, a very good place to start. Unfortunately we have only covered about 20 pages of the third grade book. There have been a couple of times where I wasn't sure what my son was supposed to do on a certain section of a page but overall, I felt the set would be worth the small investment. The sheets for this grade are grouped into little sections with plenty of practice work in each area. All your basic grade-level topics are covered in a mastery approach fashion, with plenty of emphasis on multiplication.
As for my older son, we tried to tie the Math Mammoth sheets in with our current ALEKS.com pre-algebra lessons and it made it very confusing for him. The ALEKS site doesn't necessarily present the material in the same order as the Math Mammoth site, and although I think I could look into the topics presented in each and try to correlate them, I simply didn't have sufficient time to do so.
I am no math whiz...ask me about history or language or spelling even, but not math. Ugh. So I always find the need for a very detailed explanation of each section or I cannot teach it to my children. In the older grades you get the worksheets and answer keys but no explanations. If I remember correctly, some of the author's material was originally written to coincide with tutoring sessions rather than as a complete stand-alone text. With both of us being weaker in math than other areas, I found within the first 2-3 days of use that the Golden and Green series would not be suitable for my oldest son alone, nor are they meant to be. But I am sure that if you have a child who just needs some additional practice (but already has a decent grasp on pre-algebra) these sheets would be great. Again, the prices for these products is outstanding for what you receive.
I hope that after my son has a thorough grasp of pre-algebra then we can return to the Math Mammoth sheets for review and drill work.
I would be more inclined to purchase this product for my younger son, for whom the complete set is available with explanations. :) The Blue series electronic books only cost between $2-5.50 each so it'd be pretty inexpensive to try. I would suggest getting the newsletter with the free pages/samples and then going from there into perhaps purchasing one of the Blue books to try.