Number bonds and addition number sentences

Kai is graspping the concept of addition very well and could master without using any manipulatives and just using his head to count forward by verbalise it. And we have reinforce the concept by allowing him more time to work on the quiz on the computer. He started to go beyond the number 1 to 10 and he could add more than double digits and I am not forcing him to master up to double digits since we will be coming to that later part.

We were looking at number bonds and transferring the data from it to form addition number sentences and helping him to see the part-whole concepts before we move on to story sums or problem sums. I would always ask him how he came up with his answers to check on his understanding and to see the processes that went through his heads. I am focusing more on this process then how the correct answer as I think it is important to check his understanding and the journey instead of the products. And many a time, I required him to explain to me the process and how he derive the working (number) sentence. At time, I would pretend to be the teacher and Kai would guide me to the process. It is amazing to see how he master the technique and also to crack his head when the question differ from the usual style and come up the answer and explain the processes to me.