The phrase "to plan this unit" means that someone is making a detailed arrangement or strategy for a specific project or set of lessons. Full definition
I then started doing planned unit developments — new construction single - family homes. (nreionline.com)
What we can do is be aware of the reason the brain is so responsive to video game play and keep achievable challenge and incremental progress feedback in mind when planning units of instruction. (edutopia.org)
Open plan unit with double bed and bunk bed in same room as kitchen and dining. (wikiaustralia.com)