Piaget saw cognitive development as an adaptive process. They gradually learn more about their environment and adapt. Children go through four stages. The preoperational stage is the second stage, and children go through this stage between the ages of two to seven. Children’s representational thought grows in this stage, but they have problems with logic. The concrete operational stage is the third stage, and children go through this stage between the ages of seven to 11. Children’s thought is more like an adult, and they are much more logical.Preoperational children are unable to conserve. Conservation is the understanding that even when the outward appearance of an object changes, it does not mean the physical characteristics have changes. Children have a problem with this because their thinking is rigid. They can only think of one aspect of a situation at a time, and they focus on the way things appear at the moment. Concrete operational children usually do not have problems with conservation because they are more logical.Piaget developed several conservation tasks for children to prove his theories about preoperational children and concrete operational children. I performed a few of these tasks on my six and eleven-year-old brothers. I showed them two identical tall glasses of water, and I asked them if they had the same amount of water. They both told me that they did. I then poured the water in one glass into a short, wide glass. The appearance was changed, and I asked them if the glasses still had the same amount of water. They both said that they did. I think my six-year-old brother knew because he is almost out of the preoperational stage, and he is very logical for his age. My eleven-year-old brother knew because his logic is more like an adult. I then showed them two rows of checkers with the same amount of checkers in each row. I asked them if there was the same amount of checkers in each ro...