Background:
The article gives an account of an experiment in which sixty eight high school students of age 16 – 19 developed spreadsheet applications that simulated fall and projectile motion in the air.

Materials and methods:
The students applied the Euler method to solve the governing differential equations. The aim was to promote STEM to the students and motivate them to study STEM at universities. A questionnaire survey was carried out to find out if the participants' opinion of the lessons.

Results:
The result is that 97% of the students found the lessons interesting, 93% understood the algorithms and 85% would like to continue with a more complicated task.

Conclusions:
The result implies that developing spreadsheet applications that model real dynamic systems by using the Euler method of solving the governing differential equation has the potential to promote STEM to high school students. The method can make lessons interesting, benefits the learning of the topics and contributes to the scientific and technological knowledge of the students.