Ugh..the “dreaded” pokey kid! I feel like I am a bit more sensitive to this personality type because I am anything but pokey. I speed walk everywhere I go. I rush through my chores, I drive like a bat out of hell, and I hurry through books just to get to the end of the chapter. I know how frustrating it can be to wait for someone who is meticulous, patient, and slow.
It would be best to do a little behavior analysis to see why your child is working so slowly. Is this a personality trait - like, he always works slow no matter the task? Or is he pokey because of work or task avoidance? Is he pokey because he does not understand the material? Or does he have great difficulty maintaining attention on the task at hand? See where I am going with this?
My strategies for improving would then be based on your answers to those questions. For example, if he is pokey because he is generally a pokey kid, then I might not work as hard to change him (especially in a homeschool environment) but I might adjust my own expectations. I might just set a timer and tell him he has until the timer goes off to finish the task at hand. You should administer consequences or rewards appropriately for meeting (or not meeting) those time limits. Usually, in these cases, natural consequences are pretty effective.
If a child is working slowly because of task avoidance, I generally assign “exit tickets”. I assign an age/skill-appropriate task and let my kids know ahead of time that their ticket “out” of the room (or ticket to finish a lesson and move on) is to finish that particular task or assignment. They know exactly what they are expected to do in order to be done and move on. Exit tickets are quite effective.
If your child is working slowly because she lacks confidence in her ability to complete the task or she struggles academically, perhaps a review lesson is in order. She may benefit from your moving a bit slower in your instruction as well.
When looking at how to change behavior, it is best to look at the why behind the behavior before deciding on what strategy to use to change or modify the behavior. Figure out why your child is working slowly and then base your strategy for change on the why.