Here are five example of summative assessments that could be used in STEM:

1. End of Chapter or Unit tests: This seems pretty much a standard in classrooms I have been in myself, visited or substitute teaching. At the end of a chapter or unit, a test is given that goes over all the concepts and big ideas from that chapter or unit. It could be used in Math or Science.
2. District Benchmark: I know several school districts that have district benchmark assessments. One district I know uses them in the math curriculum, every three units (each unit is twelve lessons, so every thirty-six lessons) the district requires students to take a benchmark assessment which the teacher grades. The grades are recorded and sent to the district which gives the district information about students at all levels roughly every eight weeks.
3. Portfolios: A collection of student work from a long period of time is graded based on a rubric. I can see this for an interactive math or science notebook at the end of a trimester.
4. State Assessments: State mandated assessments usually done once a year in the Spring. In third through fifth-grade students take the Smarter Balanced Summative Assessments which measure Math and ELA which are aligned to state standards. I know elementary schools are trying out the CAST pilot test which is the new science assessment for CA this spring.
5. End of Term exams: End of term exams are cumulative exams of all the material on a given subject for the entire term.  In elementary I think they would be most commonly seen in Math but could also be used in science for upper elementary.