Which conservation exercise should a nurse include in the assessment for a 6-year-old child?

The selection of comparing the mass of two balls is an appropriate choice for assessing conservation in a 6-year-old child. The concept of conservation, which refers to a child's understanding that certain properties of objects (such as mass, volume, and number) remain the same even when their forms change, typically begins to develop during the preoperational stage of cognitive development as described by Piaget. By this age, children start to grasp that changing the arrangement or appearance of objects does not necessarily alter their fundamental properties.

When asking the child to compare the mass of two balls, the nurse is engaging the child in a task that requires them to think critically about the weights of the items involved, reinforcing their understanding of conservation principles. This understanding is essential for cognitive development, as it lays the groundwork for more complex reasoning and problem-solving skills in later stages.

In contrast, counting objects, drawing a picture, or identifying colors are tasks that may not effectively demonstrate a child's grasp of conservation concepts. While these activities are important for overall development, they do not specifically assess the understanding of conservation in the same targeted way that comparing mass does. Thus, focusing on mass comparison provides a clear insight into the child's cognitive abilities concerning conservation.