I think I’m going to order a complete set of Key To Fractions.
You might also take a look at stuff from Teaching Textbooks. The combined audio/visual presentation, coupled with the keyboard/mouse input interface engages more of the human senses which makes the material connect more readily with every child’s learning style.
Son #2, in particular, was highly resistant to the read/write format of traditional workbook-type curricula, but absolutely took off once we set him up with the Teaching Textbooks Math program.
Check it out at their website, http://teachingtextbooks.com/ , but look through eBay and check with your local homeschool community to see about buying it used.