Timers are my favorite tool to prod along a slowpoke and to teach autonomy to a clinger. For my dawdlers, I figured out about how long each subject should take (plenty of resources are available online for this, or you may be able to figure it out from your teacher’s manuals).
After we had our instruction time together, I would set the timer for the appropriate length of time (say, an hour for math). If the child stared out the window the whole time, then she had that subject for “homework” later. When the timer dinged, we went on to the next subject. That freed up my time and kept pokey from asking for the grammar lesson just as I was about to start dinner. One of my kids liked to race the timer; she tried to finish each subject before the timer went off. Dawdling solved!
Timers also teach autonomy. Kids don’t even have to be able to tell time to use them. I didn’t have to keep telling my kids to hurry up and they didn’t have to keep asking how much time they had left to finish.