Abstract
The two presented quantitative studies examine the degree to which the online practiceavailable from the Khan Academy helps improve the knowledge and skills of grammarschool students. The first study, carried out in 2016/2017, focused on the transfer ofprocedural knowledge acquired via the Khan Academy online platform into the Czechclassroom context.
The second study, carried out in 2017/2018, investigates the develo-pment of conceptual knowledge through online practice or procedural knowledge. Bothstudies worked with an identical sample of 44 students, namely two same grade classes ofa grammar (high) school in Prague.
Collected data were subjected to a hypothesis testingwith a 5% significance level. At the time when the study was performed, the researcherwas employed as the math teacher of the two respective classes.
Whereas the first studyarrived at statistically significant and strongly positive results, the second study did notindicate any significant development of the students' conceptual knowledge. Secondarily,we investigated the students' views on the benefits of online practice for their knowledgeand skills.