I thought the adapted Melissa and Doug abacus would be sufficient but the design didn't turn out as well I planned, I unknowingly cut the rods too short. Whenever my overzealous son manipulated the beads, he used too much force and the beads would bounce back instead of effectively staying in place against the answer bar. Darn it.
We started out by using my iphone to teach the kids to count to 100 on the soroban using the Talking Abacus app. They have it for the ipad as well. It worked out beautifully because the kids were able to learn without me standing over their shoulder and I could easily hear how they were doing nearby.
They already knew how to count to 100 from memory, so the app provided immediate feedback. It announces each number when they set the beads. My daughter self initiated some skip counting practice on it, as well. After they learned to count to 100, we then began the Abacus Adventure app (ipad only) which parents on the BrillKids early learning forum had highly recommended.
It was an immediate hit! The kids loved the idea of saving the princess level by level and were motivated to play it. I can actually hear my son on the couch playing Abacus Adventure as I type this, although we do it together most often. :) Overall, I am really pleased with it and it's finally allowed use to make some progress in this subject. It's a little buggy and does freeze up from time to time when the kids get "scroll happy" going up and down too quickly, but they know not to do that now for the most part. If it happens, we have to reboot the machine and it works fine again.
There are a couple of hurdles we needed to get over for my kids to be successful with this. One of them is the Mental Math visualization levels. They are starting to learn soroban relatively young and while they are picking it up nicely, they are still working on their visualization skills. They are not yet able to solve all of the problems in their head, which makes the mental math levels a challenge. Not being able to advance through these levels would which greatly dampen their interest until their visualization skills caught up with them. I feared with that kind of stall, they would lose momentum and motivation with it. So to get around that, we utilize the pause button to solve the problem on a physical abacus (with more time and Mom's help if needed), then resume play and enter the answer. We fit in their visualization practice at other times.
However, as I mentioned our homemade abacus wasn't working out too well, and my daughter's cheapie ebay $5 special was too small for my son to enjoy. It's okay, but it fell apart the very first day, no joke! LOL We had to pick up every single bead and reassemble it with packing tape. At the time when I bought it, I wasn't sure how this was going to go so I didn't want to put out a lot of cash. I liked how the longer rods gave her more room to work, but the edges of the beads are not smooth and it's just very lightweight. It's closer to junk that quality merchandise but it will get the job done for an absolute novice.
So, I went back to the drawing board and took apart our 100 bead abacus, rigged it up with a ziptie, and used that until my brand spankin' new super duper fantastically beautiful teacher soroban arrived from Japan! ::swoon!::
If I hadn't ordered the new one, I would have chopped the base in half so it layed flat, removed some of the rods (which can be done by wiggling then in a circular motion, and bought a piece of wood to attach for the answer bar. But, I was ready to invest the money and be done with it, and I am very glad I did. And man this thing is BEAUTIFUL! The craftsmanship is just spectacular, I was just in awe after I really sat down to inspect it. At $163, it was much more than I wanted to spend, but it is very high quality. The kids LOVE IT! And I do too. :) Already it's got some minor dings in it here and there from being knocked in the fireplace, etc, but I would rather it be loved and used by my kids then pristine in the closet. I added some adhesive felt circles to the bottom and back to protect it as much as possible. I love that I can stand it up and show both kids at once, but the kids need to lay it down so they don't knock it over. I don't think this is going to help them develop speed by any means, but it is absolutely better for my kids to manipulate at this stage. My daughter could have gotten by without it, but my son is just taking off and I think even passing her now in enthusiasm and skill at the moment. My only regret is not buying it sooner!
It took about 7-10 days to arrive from Tomoe Soroban in Japan and the customer service is excellent. They responded to my question over email quickly. When the kids are ready for an abacus with more rods, I will not hesitate to order from them again. I believe this was the company recommended by SorobanTom, as well.
The second challenge I had to figure out was the issue of the knowing number bonds of 5 & 10 by heart to advance through the levels of Abacus Adventure. A dear BK friend was kind enough to give me some spare cuisinaire math rods she had a while ago, so I dedicated a few of them for use with the abacus. I am so grateful to her for giving them to me because my kids really enjoy them! And I probably wouldn't have had a reason to get them otherwise. I used my label maker and scotch tape to attach them together, and now we keep our big and little "friend sticks" in a ziploc to use during abacus time for quick reference. They are mostly for Owen because Lily has been exposed to the concept of number bonds through more Singapore Math then him, but soon enough he won't need them at all. I think of them as abacus training wheels. :)
Alternatively to creating number bond sticks, you would just use a 100 bead abacus to figure out the "friends" each time. Since mine was rigged up and in use, this was an easy fix. You could also make some homemade out of popsicle sticks or just use unifix cubes. However, I know my kids and those interlocking cubes can be a distraction because they're just so fun to take apart! :)
We have been dabbling in the Nurture Minds workbook but it's a bit slow and my kids are so techy, they seem to prefer the ipad. I am still kicking around getting some instructional videos to help reinforce concepts, we'll see. Math Genie offers addition and subtraction now, but will release multiplication and division in the next 3-6 months. They were very nice on the phone and said if you get stuck, just email them for coaching/questions as you go. They recommend one lesson a day. We still use Math Secret off and on (and I do intend for the kids to work through the curriculum one day independently, even if it's review at that point) but for the moment our current approach is working well.
Anyway, that's been our abacus experience thus far. The kids have made such great progress in a short amount of time and the above tools have really helped ME understand this subject and teach them better. Remember, you don't have to be able to calculate 14 digit numbers in your head to teach this....just stay one step ahead. :)