A few years ago my mom was telling me about Hands on Equations they were doing in a 6th grade class she was working in. (She is a teacher as well) This really peaked my interest in what this was and maybe something I could use in my classroom.
If you have never heard of Hands on Equations, let me give you a little background info: About Hands on Equations (follow this link to the company webiste)
Demystifying the Learning of Algebra:
Making Algebra Child's Play
Hands-On Equations is a supplementary program that can be used with any math curriculum to provide students with a solid foundation for success with algebra. It uses the visual and kinesthetic approach developed by Dr. Henry Borenson to demystify abstract algebraic concepts. The program enhances student self-esteem and interest in mathematics.
The basics behind this is students can solve an equation like this, 2x+x+2= 12+2x using pawns, cubes, and a balance sheet. It is always so amazing to me that my students learn to solve these equations so easily.
Here is a demo about it I found on YouTube:
This is not a curriculum but a supplemental activity you can use with your students to make algebra more concrete before moving to the representational. It is so engaging!!
(P.S. I am not being paid or compensated for my recommendation. Just telling you what we are doing that is successful in my classroom)