Introduction to Psychology 10th Edition by Rod Plotnik,Haig Kouyoumdjian

Exercise 3

The third stage, which lasts from the age of about 7 to 11, is called the (a) _____ stage. During this stage, children can perform a number of logical mental operations on concrete objects (ones that are physically present). The idea that the amount of a substance remains the same even in different shapes, known as (b) _____, is mastered during the third stage.