I teach 7th and 8th grades. For both terms, sequencing and algorithms, I give a formal definition which students do need to place in their notes. Then to get across the idea of sequencing, I give them a short series of verbal steps that have them move around their desks.
For the algorithm, I'll have students in groups and give them the task of writing directions around to move around a portion of our field. Each group must begin and end at different parts of the field. They must write these steps down, then they will trade with another group and each will see how close they get to the intended mark.
We'll debrief afterwards in the classroom and talk about what worked and what didn't.