R.M.
Hi D.,
No matter how much attention you provide your 4 year old, they always need that reassurance that you're there. It is part of their development. When they feel that you're there to catch them, they wander off on adventures which they may fall from.
When I needed to get things done, I would tell my charges, (I was a Nanny), what I needed to do, and what they needed to do. This often worked. If I gave them tasks, they were focused on those tasks rather than what I was doing.
Good Luck.
R. Magby