So my wife bought my daughters some simple math books. They have add and subtract etc in them. Callie came upon Alyssa, she is 5, working in one of the books for fun and was happy to see she had made it through the simple problems with ease. We haven’t spent much time teaching them match yet so she figured she was doing quite well. Then she noticed Alyssa had started into the harder problems, 5 9 etc, and was surprised to see she was getting the correct answers. Amazed she continued to watch to see how it was that she was working out the math problems. Inspite of the fact that our kids have never had any exposure to textbooks, Alyssa turned to the back of the book, found the answer and then copied it into the correct location.