In this paper we discuss caracteristics of external differentiation and its influence on student’s
achievements (at mathematics). We are going to present some aspects (advantages and
disadvantages) of external differentiation regarding the efficiency of gaining mathematical
knowledges for achieved level of mathematical knowledge in homogenous and diverse study groups.
The results are indicating that there are no homogenous answers, especially not if we limit ourselves
to the outmost poles – on the most capable students and on students with learning difficulties. It is
expected that school and a teacher enable each student to be educated with suitable approach that
support his potentials. That’s why we understand the capability on one hand and learning difficulties
on the other as a challenge to the teacher to find appropriate way of how to teach, how to recognise
student’s needs and which measures to choose that the achievements of students will be optimal
regarding their abilities and capabilities. The key question regarding the goals of gaining qualitative
knowledge for all is how to adapt learning to all students, considering their needs and potentials and
thus lower eventual deprivation of more capable students and students with learning difficulties. This
dictates the need for developing of suitable approaches of learning and teaching for all.