I have started a homeschool sale page here that I update monthly. I will be posting all current homeschool sales there, including Mammoth Math.
Mammoth Math is periodically on sale through Homeschool Buyers Co-op. Homeschool Buyers Co-op is free to join and works to provide discounts on a variety of popular homeschool curriculum choices. If you join the Homeschool Buyers Co-op, you can be kept up to date on their curriculum sales.
CLICK HERE to go to the Mammoth Math page on the Homeschool Buyers Co-op website.
#1 Way to Save
The Light Blue Series is the graded level program. You can get the full downloadable light blue series (1st through 7th grade). This is an amazing deal for a math program you can reuse with multiple children.
CLICK HERE to read more about how to select a math program and about Mammoth Math.