Tasks with multiple steps

Hi, if you give a child a task that has multiple steps, say they need to pick up all the small trash cans and bring them by the big trash can, and they do it all but forget one small trash can, how do you deal with this? Do you 1. Consider the task done because it was 90% done or 2. Remind the child of the missed trash can and have them complete the task fully or 3. Do a correction for the missed step?