Purpose: The purpose of this paper is to explore whether and how principles from variation theory can contribute to the planning of teaching and learning beyond learning study. Design/methodology/approach: We study whether and how principles from variation theory contributed to a group of teachers' planning of teaching and learning about decimal numbers in Grades 4 to 7 working in Subject Didactic Groups - a collaborative arrangement suited to daily teaching. A theoretical thematic analysis approach was used when analyzing eight audio-recorded meetings and written documents. Findings: The study shows that variation theory principles contributed to the teachers' planning of teaching and learning. Two themes were identified: the theory contributed to the teachers being able to (1) specify what their students needed to learn and (2) design tasks that they anticipated would afford the opportunity to learn what was identified as being necessary to learn. Originality/value: The paper demonstrates how variation theory can contribute to teachers' planning of teaching and learning when used in a collaborative arrangement other than learning study. This leads into a discussion about variation theory being used separately from learning study and the benefits and limitations this other collaborative arrangement can have for gaining knowledge of what is to be learned and taught.