By age 8, most children realize that while irises and geraniums are different types of flowers, they are both flowers. In other words, 8-year-old children have mastered the logical ability of:

Classification

Explanation: Classification simply means the ability to group or segment objects, species or materials into classes or divisions based on various characteristics. The characteristics employed in grouping objects or species belonging to a particular class must be present in all species belonging to that class of objects or species. Classification is by an individual's clear or sound reasoning.

The ability to realize that geraniums and irises are flowers is a mastery of logical Classification, even though they could still possess difference such as sepal length, color and so on which could be used for further Classification.

chronological thinking is an indispensable tool to structure a historical narrative and to give meaning to a sequence of events. the final section presents the results of a survey to test the chronological thinking of lower secondary school students carried out by the educational research institute.