A group of maths teachers collaborated with St. Louis Dundalk in collaborating their ideas and designing a lesson as part of Lesson Study. This is a great opportunity for Teachers in the area to collaborate and design a lesson for a group of students. The college has participated in Lesson Study in recent years and have enjoyed collaborating with different schools in Dundalk. Lesson Study is recognised internationally as being the most-effective form of professional development in changing classroom practices. Teaching through structured problem solving is widely acknowledged to develop students’ ability to think mathematically and to solve problems.