Abeka- expensive for the quality, lower grades are the same as a workbook purchased from Costco. Have a second grade student workbook. Too expensive for what it was.
Saxon- very heavy on the parents side, time consuming. Rote memory and not much of the fun reasons to love math. Spirals daily, meaning it goes over all the past learned skills. Skills are mastered but it can feel painful for some students. Have 5/6 and 6/7 books. Pages look overwhelming to some students, large amount of daily practice.
Investigations- K - 5- like it a lot, kids like it and master the skills, attain fluency due to how it's set up. there are areas to draw out or solve problems in multiple ways. Only a few problems on each page and it builds as it goes. there are student work books and a hand book. I found that I didn't need a teachers manual for k-3 at all and in 4th wanted the unit manual for some units like the fractions section. It is mental math, showing all the work isn't the emphasis. Knowing how to get the answer is the goal. Also is affordable to purchase workbooks for each student. I got unused but worn copies second hand for $10-15 on line at places like abebooks.com and amazon.
Connected Mathematics- 6-8- written by the University of Michigan and are very science oriented math skills, everything taught pertains to real life situations and the graphing sections are actual scientific data, like the ratio of the femur to the height of men and women. It does not spell out the basics for the parent/teacher. It needs a math whiz to teach it, I am not this. We did really really love the amazing feel it gave us for what math can do, it is great for science minded people. Shows the outside the box uses of math. More reading than in other texts, again about life uses for the concept being covered. Units cover probability, statistics, geometry, algebra and everything else! Most of it was over my head even with teachers manuals. BUT so worth it!
so we were introduced to Math-U-See by a friend, we borrowed the pre- algebra and completed it in 6 months, three kids did this. A girl 16 whose struggled because she went through too many different math curriculums trying to pick a good one. And two kids in eight grade, girl 14 and boy 12. I handed them the teachers manual and student book and they primarily taught them selves, I helped clarify when asked, they also watched the video of the writer of the program teaching the lesson if they needed more help. It teaches the necessary basics quickly and concisely, no hammering it into the ground with too many problems or too long of lessons. it is not designed to take 160 -180 school days or a school year to accomplish. The levels are to be done in order as the student has mastered(tested well) the lessons they move on. Very simple, it is however boring, not creative or shows almost no use in life. (keep a clean copy of the student work book, when the publisher/owner reprints or edits and updates his curriculum he no longer prints old versions of the manuals. The curriculum is $77 for elementary levels and $35 for student books.)
My intent here on out is to combine it with Connected Mathematics! I am going to use Math-U-See as my basic lesson and add spice to it by supplementing with the fun applications in Connected. I will let you know in a couple years how this pans out, I am making notes in Connected as to which Math-U-See lessons/grades to complete prior to doing the Connected Mathematics.
My recommendations are to use one math all the way through, any of these work well for the families we know. Just don't switch every year like I did, searching for the perfect math. They all get the job done in different ways. Stay with one, my top recommendation would be Math-U-See and second would be Saxon. Unless you're a math whiz then definitely use Connected Mathematics for 6-8th and use mathusee with it and for the other grades. Raising a little engineer or scientist would be easy with Connected.