1. Piaget's Concrete Operations concrete operational stage of development can be defined as the stage of cognitive development in which a child is capable of performing a variety of mental operations and thoughts using concrete concepts

2. STAGES OF CONCRETE OPERATIONAL

3. Conservation Conservation is the understanding that something stays the same in quantity even though its appearance changes. To be more technical conservation is the ability to understand that redistributing material does not affect its mass, number, volume or length.

5. Conservation

6. Decentration Decentration involves the ability to pay attention to multiple attributes of an object or situation rather than being locked into attending to only a single attribute. When children are asked to compare the volume of Apples, it is their ability to decentrate that enables them to flexibly consider both the height and the width of the Apples in arriving at their decision. Through the development of decentration skills, older children start to be able to pay attention to more than one thing at at time.

7. Reversibility Reversibility takes conservation one step further. Children capable of conservation appreciate that an object's quality is not altered simply by transforming how that object appears. Children capable of reversibility appreciate that if an object's quality is altered through some true subtraction or addition, the object's original quality can be restored by reversing the alteration. This capability is enabled in large part through the maturation of children's memory so as to enable their retention of awareness of a series of events and their ability to run backwards through those remembered events so as to see how something transformed could be restored to its initial state. An example of this is being able to reverse the order of relationships between mental categories. For example, a child might be able to recognize that his or her dog is a Labrador, that a Labrador is a dog, and that a dog is an animal.

8. Reversibility

9. Classification Beyond conservation, Piaget also believed that children in middle childhood master hierarchical classification; the ability to simultaneously sort things into general and more specific groups, using different types of comparisons. Most children develop hierarchical classification ability between the ages of 7 and 10. The ability to perform hierarchical classification is very useful to children in school, as they begin to understand and appreciate science and social studies concepts which involve making just such comparisons, for instance, sorting living creatures into different groups based on whether they are animals or plants, etc.

10. Classification

11. Seriation The cognitive operation of seriation involves the ability to mentally arrange items along a quantifiable dimension, such as height or weight.

12. Transitivity