Miriam is testing a concept that she learned in her child development class. She takes ten pennies to the preschool where she is doing her internship. She shows the children the pennies and asks them to count them. Then she makes two parallel rows of five pennies in each row that are both evenly spaced so that the rows are in alignment. Then, as the children watch, she spreads the bottom row out by increasing the distance between the pennies. She asks the children which row contains more pennies. They all respond that the bottom row has more. This illustrates that the children are unable to solve ___________ problems.

Conservation is a stage that occurs in the concrete operational stage. In this phenomenon, the conservation is to understand the quantity stay the same even if the appearance has been changed of the objects. If technical we try to understand it is about to understand the redistributing the materials.

The distribution of the object does not affect by the number, mass, and length and its volume. Around seven-year, children understand the conservation of whether the appearance has been changed. Five-year children do not develop conservation so they think there is a difference in the quantity of water if the appearance has been changed.