Answer:
The answer is: Juan is showing a lack of conservation.
Explanation:
Conservation is a concept included in Piaget's cognitive development theory, according to this theory, conservation is the child's ability that allows him or her to understand that the quantity of something doesn't change even though the appearance changes, even though it might change its shape, form, number or the container it is in. According to Piaget, this ability is part of the concrete operationl stage of cognitive development, and it is when the child is around seven years old.
In this case, even though Juan sees that both of the cookies are the same size, when his mother breaks Anne's cookie in four pieces he is not able to understand that it is still the same amount of cookie, instead he thinks that she has more because she has more pieces than him.