According to Dearlee

According to Dearlee (1962) any topic in mathematics depends on six major factors. These factors are, the suitable acquaintance with past work, environmental factors controlling the provision of suitable perceptual experiences at the stage about to be reached, factors personal to the individual such as degree of intelligence to learn further, concentration or attention span, willingness to learn further, individual environmental relationship controlling him or her such as interest, attitude, teacher-learner communication, maturation level largely affect the ability for making or grabbing concepts and the quality of teaching at different stages. This means that every individual is influence by both internal and external factors around us.