Math Mammoth produces math materials to fit almost any math need for a homeschooler (and perhaps even for a traditionally schooled student that could use extra practice). In the past, I've used their Make it Real Learning materials to show my older students how math applies in more complex real life situations (for instance, choosing the best deal on a cell phone plan). I've also purchased materials in their Blue Series to teach or review a single topic. Recently Lauren has been using their complete math curriculum -- the Light Blue Series for Grade 2.
Math Mammoth calls the Light Blue materials a "worktext" where "work" refers to the practice problems and "text" refers to the explanations. In other words, this curriculum is completely self-contained. There is no need for a separate teacher's manual to show how to teach the concepts because the instructional materials are written directly to the student and are presented step by step in the worktext.
One of the strengths I've found while using the Math Mammoth materials with Lauren is that it focuses a lot on mental math strategies. For instance, Lauren's assignment for today is practice with subtracting whole tens. The worktext uses pictures to illustrate the tens and the ones so that students can visualize what it happening with the problems. After four illustrated problems, the intent is that the student will be able to see patterns emerging and can easily calculate the answers for the rest of the problems on the page.
Math Mammoth uses visual models to demonstrate the concepts and all of the pages have clear illustrations, such as the bars and cubes above or the boxes and dots below.
I suspect the Math Mammoth materials would work better for Lauren if she was developmentally ready to work without using hands-on manipulatives. She still often needs to use physical objects to illustrate the math problems. Thankfully, I'm comfortable using either the math manipulatives we already have or making some new ones to fit the lesson.
In one place on their website, Math Mammoth does suggest that lower elementary students use an abacus to help add a hands-on component to the curriculum. If Lauren gets tired of our pipe-cleaners and beads model, perhaps I'll find an inexpensive abacus for her to use when illustrating addition and subtraction problems.
Overall, I'm very impressed with the Math Mammoth materials, and I'd recommend the Light Blue Series as a solid math curriculum for elementary students.
A full year of the Light Blue Series math worktexts costs $34 to download as a pdf. For ease of use, I printed my materials and had them spiral bound at an office supply store for just a few dollars. The Light Blue Series is available for first through sixth grades.