Thank you so much for your update Lori! It is greatly appreciated to see where the little ones are not that they are growing up.
I love that your son has a passion to learn. I too believe that despite his setbacks that he will do well also.

Preschool prep is 50% off right now.

I absolutely loved reading your post!
You came up with a lot of good extension ideas for number crew. I look forward to seeing more.

I was going to suggest Snap circuits! We just got my son snap circuits Jr for his 4th birthday and he can't play it enough. I felt like a fool today when he had to correct me about which piece was a diode and which was the resistor.

We also access number crew from Discovery Streaming.

As for counting there is a lot to do to meet mastery. I am just going to list those things. Just ask and I will explain anything if you need more detail. The things listed below don't need to be taught in the order I have stated. My son learnt subitizing, numerals, counting backwards and forwards and then counting on. Cardinality and bijection he learnt last. Which may be attributed to his counting weakness. But he is strong in all other Math areas.

Counting backwards and forwards
Counting on
Cardinality
Bijection
Numeral association

Bonus things to know for number sense.
Ordinality
Parity

Then the rest of early math is all concepts. Shapes, measure, comparisons, locations.

At 19 months you have a choice in how you wish to teach arithmetic. You can teach if after all the other math stuff has been mastered, or at least a child has become familiar  with a lot of it. This is a manipulative heavy approach. Or you can teach arithmetic right after a child knows numerals and how to count.

Milk isn't a necessary part of a diet. Humans are the only mammals that drink milk beyond infancy.
What is essential is the calcium and vitamin D. You can use other foods to reach the acceptable amount. Other dairy products such as cheese and yogurt are a good source. But fish like salmon and broccoli are good also. There are also calcium fortified Orange juices. Worst case scenario... An anti acid or other calcium supplement will meet her needs.
I don't drink milk. I haven't since I was a very young child. I have no calcium deficiency.

Counting is my son's weakest math skill. I agree about mastering counting by 1s before skip counting.
Something that I should note. I never taught my son to count above 20. I taught him 0-20 backwards and forwards. He was able to figure out how to count any number beyond that by learning the pattern. Once he had mastered counting to 20, I next was able to teach him skip counting by 10s. A Hundreds chart helped a lot. Next it was skip counting by 5s. Using all the family members hands and feet, and tally sticks helped wiifh that. And next we taught skip counting by 2s as we focused on parity. By making those association I think it did help with decreasing any confusion. Coins can help with skip counting also.

I agree with Manda. He is old enough to understand the circumstances. If he asks stick to your guns and say No. He can only nurse before sleeps. Don't waiver from this rule. Ans be expected to tell him over and over.

We are going through something similar. My almost 4 year old is an avid thumb sucker. Personally it doesn't bother me. But I have issues with the hygiene aspect, especially in social situations. So we have created a stringent rule that he is only able to suck his thumb before going to sleep.  We don't have to fight the issue, and he knows what he can do. 
I think nursing is a similar habit to break.

They were emergent readers. They could read level one easy books.
Books that said the same type of sentences over and over with a lot of sight words.
I like blue cars. I like blue balloon. I like blue fruit.
That kind of reading.

Then for 2 years they went into a traditional daycare that did a little light academics. They would bring home a letter of the week worksheet. When I saw them at this point they could not read the simple books that they once read easily. But when they did go into K they flew up the reading ranks. They were at a second grade reading level by the end of K. They are now in 2nd grade and they can pretty much tackle anything they want to read, if they choose to do so. But they don't read a lot. Mostly just the required school work reading, and maybe a few minutes before bed. Sometimes this is like pulling teeth though. They have a preference to non fiction and they read it well, with comprehension. They like to sit in the same room reading a book and tell each other random facts from the book that they are reading.
They have yet to read a chapter, or even chapter type book (think Frog and Toad).

As to your questions... Maybe they didn't lose the ability, maybe it just became dormant for 2 years. I have no way to tell. It is quite possible that they would have learnt to read just as easily without any instruction also. Was it worth it to teach them? Definitely. We had many fun times snuggling up reading many books over the years. If they had kept reading between 3 and 5 would they be better readers now, would they love books more? Maybe, maybe not.

Yes I meant to mention that it was like what Khan proposes.

My concern is the sample. Would homeschoolers participate if their children were struggling? I would love go see a large scale study take place. But the logistics are tricky.

I ultimately do believe that homeschooling has the best education benefit that public school could never replicate. Homeschooling has the ability to give a student one on one direct, catered education. Not just a short tutoring session either. But a full on education.

I envision schools of the future being different, more technology driven. Children can learn an amazing amount being "self taught" via apps, videos, reading. But the teachers role changes. They become less of an instructor and more of a mentor. They can help the students who are struggling. Sit one on one with them, or in small groups. Or they can pair students together to help others. 

I was In an experimental class when I was in 5th grade. It was a 5/6/7 composite class with about 6 students from each grade. I was paired with a 7th grade student who was to instruct me in math and writing. I remember many hours sitting on the floor comfortably doing school work. I have no recollection of my teacher actively teaching us in the class as a whole.  We taught each other most of the time. For geography we were split into groups of 1 student from each grade. We all studied several countries. And then each group had to teach the class. We did presentations and wrote quizzes and worksheets.  I remember more about the countries that we studied that year in school that any other geography lesson throughout my years of schooling.
By the end of 5th grade I was working on 7th grade work. All the kids in the class actually covered 2 years of schooling. Sadly the program was nixed and we all went back to our respective grades the follow year. And we basically did a repeat year. I was not impressed. That was the year my opinion of school diminished.

Times are changing and I think college is becoming more and more essential. Years ago my mum only completed 10th grade highschool. A generation before that it was 6th-8th grade highschool. My generation it was expected and perhaps necessary to complete highschool. And I suspect when my child is old enough, he will need to do college.

I do agree that there are some exemplars. Gates, Branson, Zuckerberg etc. But not everyone has an innate ability, the dedication and the passion to do what they did. Sadly I know too many kids that use those people as examples for why they don't need to do their school work. And these are kids who, I believe, need that education.

Thanks frukc. I found it.

Could anyone provide the name or the search parameters for the video? I really want to watch it. For some reason every time I try to open it here on my iPad the browser app closes. I would like to search for it on YouTube.

Thank you.

We use BFSU. we don't complicate things. I read the topic. Jot down things to add into our daily discussion. I then borrow relevant books or DVDs from the library. I use discover streaming and YouTube if need be.
We don't do experiments much. Right now we are just building a knowledge base. At the end of the week James dictates a few sentences about what we learnt in science this week.
Currently we are deviating a big and focusing on the systems of the body more deeply than BFSU does.