This book contains advice about writing Tutor Marked Assignments (TMAs) for Maths, Science and Technology courses, which may be particularly welcome to students in the early stages of studying for an OU qualification or who are contemplating study with the OU. Planning, layout and structure together with content aspects of writing TMAs are considered, with examples. TMAs with a strong mathematical element, those which involve a combination of description and mathematical working, and those which are more "biological" in content and essay in type, reports and web pages are included. The author's credentials for writing this book are that she was a student at the OU from 2000-2010, and wrote upwards of 80 TMAs during that time, from entry level 1 to level 3 honours. These included TMAs for Mathematics, Science and Technology courses, the author finishing with 720 points and two B.Sc. honours degrees in Mathematics and MST (Open).