I use text books and assign problems. An unschooler would tend to let the kid explore and learn what interested him in whatever manner interested him, with the parent being available to answer questions and point towards resources
It's harder to explain than it is to do, but it does require a relatively large investment of time.
Here's the Readers Digest version:
1. Make sure the child is always involved with some project that he/she is interested in at that point of their life, (something valid, meaningful and mutually agreed to, of course).
2. Do step # 1 thoughtfully and you automatically have their full attention and focus, as opposed to "watching the history channel" at a mandatory time when their attention is far removed, (daydreaming).
3. Do the project/activity with the child.
4. Connect the project/activity to real world, real time instruction. For example, (albeit an extreme one), I once taught a killer geometry class while fishing. Taught my then six year old all about angles while angling. Living the good life and learning at the same time.
5. Enjoy and cherish the time you have together.
I hope this is somewhat understandable.