I use Rays, with the assistance of Ruth Beechicks guide. I alternate it with Developmental Mathematics (another inexpensive curriculum). They balance each other’s strenghs and weaknesses; I use Ray’s purely orally and then with D.M., I have a workbook to use, too. I use each two days a week.
I believe Ray’s is very thorough and I think the math skills of our ancestors (for example, those that calibrated the space launching and moon landings and return without a computer!) were strong enough for me to use what they did.
And yes, I can use it with both of mine for 3 years; I bought it used for 3.99, but it’s still a steal new. However, you do want to use Beechick’s guide with it.
Rachel