Two content topics will be described. One deals with geometric measurement: length, area, and volume. These are important topics and they have not been learned very well. In particular, what types of relations can one consider when dealing with these three aspects of geometric measurement? The second topic is fractions, and different views of what students should be expected to learn. A third topic will be briefly discussed. This is a new book which has many mathematical topics which arose in secondary classes, with comments on the content both as it relates to student learning and sometimes how the mathematics fits into what had previously been studied in earlier grades and also how the ideas fit into later material. The aim of the work was to set up a framework on mathematical content knowledge for teaching mathematics in secondary school. The authors asked for comments from readers, so some will be given. [For the complete volume, "Mathematics Matters in Education: Essays in Honor of Roger E. Howe. Advances in STEM Education (ASTEME)," see ED607653.]