The Simple Pendulum and experimental uncertainties

[aaa_]

In my schedule, I take 1 reading.
Example: Length(m) is 0.9m and time for 5 oscillation is 9.5s

(0.9m is longest length) How do I calculate the uncertainty sir? Since the questions required me to calculated it. Or...

Updated: I already found it. The least count of stopwatch÷ time of oscillation.

Is this correct