My granddaughter is a math whiz, and she became a teacher. When she was a tiny child, she came home with her math homework. She was stuck on multiplication and division. So, I showed her that multiplication is just a shortcut to addition, and division a shortcut to subtraction.
I used simple examples such as the one in the op. In that one sitting, she grasped the concepts and ran with them. She caught on so fast she was ahead of her class.
By the time 4th grade rolled around, she was teaching herself intermediate algebra from my college text books. She understood that book better than I did.
Some of the common core math is ridiculously complicated unless you already have good basics.
Different people have differenSome learning styles, and that goes for kids, too.
Indeed. I was 9 weeks into my sophomore year in high school. My sinuses were not doing well with the band field shows. I arranged to swap band for chemistry. Everyone in that classroom was a junior or senior. My dad recommended cracking the textbook for the class and doing all the chapters and questions to catch up. It was 3 1/2 weeks later that I finished the whole book. Easy A. The next year I was a senior (having accrued enough credits to rate the class standing). The pattern continued until I graduated from UCSD at age 19. Give me the book and in due course it will be mastered.