The Organization for Economic Cooperation and Development [OECD] is a global policy organization that includes the United States and about half of the Western Europe countries. It administers international comparison tests, called Programme for International Student Assessment (PISA), for 15 year-old students in Mathematics and other subjects. I present what I believe the PISA mathematics results really tell us. Among other things, the results suggest that students need more instruction in multi-step Arithmetic word problems and more practice with Arithmetic calculations. Also, students should not be rushed in Algebra in Grade 8. The results suggest that PISA is not a valid measure of the overall quality of mathematics achievement in a country. PISA mathematics largely avoids measuring Arithmetic calculations.