There are tons of math options for 2-3 grades! Depends on what style you're looking for, I suppose. How about if I rattle of a list and you can look them up here for reviews:
Cathy Duffy Homeschooling Curriculum reviews
* Horizons (workbook, ahead of most, spiral)
* Abeka (workbook, ahead of most, spiral)
Teaching Textbooks (computer, starts out behind but catches up)
Rod & Staff (dry & old school workbook, starts out behind but catches up)
* Miquon (hands on, challenging, mastery)
Math-U-See (hands on, mastery)
* RightStart (hands on, challenging, mastery... I think)
* Life of Fred Elementary (in storybook form like the higher series is)
Saxon (workbook, usually right on target, spiral)
IXL.com (computer, supplement mostly, mastery)
* Primary Grade Challenge Math (workbook, supplement, challenging)
Those with astrisks are ones I'd recommend for kids who are naturally good at math. The others are ones I'd recommend for kids who need a lot of instruction and/or practice.