Observation of Cognitive Development

I was assigned in class to conduct cognitive activities with a child. One activity that I performed was with a eight year old. I had two equal balls of play-doh and I asked the child if the two ball of play-doh was equal in the amount that was there and he agreed that they were. Then I smashed one of the balls of play-doh and asked the child if the two things of play-doh was still equal in the amount that was there and the child answered yes again. Since the child answered yes to both my questions he is thinking on a concrete level according to Piaget's Cognitive Development Theory.