In the process of teaching Mathematics, identifying and selecting integrated content with other subjects to design teaching according to the STEM education orientation will help students see the meaning of applying the knowledge and skills they have learned to solve practical problems. The article presents some issues about STEM education and proposes steps to design STEM educational activities in teaching Mathematics 1, contributing to improving the quality of teaching Mathematics in primary schools.In the process of teaching Mathematics, identifying and selecting integrated content with other subjects to design teaching according to the STEM education orientation will help students see the meaning of applying the knowledge and skills they have learned to solve practical problems. The article presents some issues about STEM education and proposes steps to design STEM educational activities in teaching Mathematics 1, contributing to improving the quality of teaching Mathematics in primary schools.