In this article, the use of formative and summative online quizzes within a distance learning introductory mathematics module at the UK Open University is described. The rational for introducing such quizzes is outlined, together with how the quizzes are embedded within the module. The use of the quizzes by students is analysed, in terms of the number of attempts made and when they occur, and the results achieved. It is found that the number of online summative assessments closely matches the number of submissions of written assignments, and that the marks are strongly correlated. The usage of formative quizzes was lower than that of the summative assessments, but they do seem to be appreciated by students who use them, and they are used in preparation for the summative assessments.