1.
several vehicles or machines; a few units
An unspecified small number — usually a few to several — of things counted with the counter 台 (cars, machines, appliances). The prefix 数 attaches to a counter to mean "several."
車が数台止まっている。
Several cars are parked.
会場にパソコンが数台並んでいた。
Several computers were lined up at the venue.
工事のため、道路に重機が数台入っている。
Several pieces of heavy machinery are on the road for the construction work.
The prefix 数 attaches to a counter to mean "several" or "a few" (typically two to eight or so). With 台, the counter for vehicles and machines, 数台 means several cars, computers, appliances, and the like.
THE 数〜 PATTERN:
- 数人: several people
- 数回: several times
- 数日: several days
Use 数台 only for things counted with 台; switch the counter to match other kinds of objects.