This article considers the issue of implementing a model of blended learning to prepare master students majoring in Mathematics (speciality code in Ukrainian educational system “014 Secondary Education. Mathematics”). The research analyses the existing developments of the issue about the use of blended learning while training would-be mathematics teachers. The researchers determined and explained the stages of work on developing the online course “Methods for Teaching Mathematics to Students at Technical Universities”, that is used when students learn methodological subjects of the curriculum.