If you are looking at Gattegno you must go to Sonya's FB group and websites at ArithmophobiaNoMore, Learning Well Academy and FB group-Homeschool Math with Base Ten Blocks. She has used Mortensen and Gattegno for years. She has read all of his books and has personally taken training at one of the only schools in the country to still be using Gattegno. She is a wealth of knowledge and understands Gattengo and the use of the rods like no one else. She is also friends with Ana.
I originally started with Mortensen/Crewton and then learned about Gattegno from her and made the switch years ago. She convinced me the C-rods were better than Mortensen because they didn't have the unit marks on them and having used them for several years with Gattegno's books I have to agree. There is much more you can do with the C-Rods, even though you can still use the Mortensen blocks if you turn them on their side. ou can buy the entire set with c-rods from an online shop in the UK. That is what I did and the rods are amazing quality. Gattengo does require parental involvement to implement, but the way he teaches math is brilliant! Sonya has done a lot of the leg work and offers several courses for kids using Gattegno material to make it easier for parents, but you absolutely don't have to take them. You can still go through the books on your own and still get so much out of them.
One other thing, Mortsensen/MathUSee and Miquon basically took Gattegno and made it a curriculum that is more open and go, but unfortunately some things were lost. Having the unit marks on the rods was a big one and another is the notice and wonder aspect. Have you ever watched any of the old Gattegno videos on youtube? Watch those and you'll see what I mean. Sonya does a wonderful job of explaining all of this on her websites and her FB group, which is very active. She has modules and training that make it easy to see how Gattegno works. I highly recommend joining the FB group and looking and going through the guides. Ask away, she loves helping parents! I'll drop links below.
~Melissa https://www.facebook.com/groups/arithmophobianomore/learning_content https://www.learningwellathome.com/academy/ https://www.arithmophobianomore.com/