What's fun, and very interesting for both children and adults, is going zero tech. In fact, go back to prehistory.
You start with the different properties of stones. If you have flint, obsidian, granite, quartzite, gypsum, and calcite in your region -- find them together. If not, buy them. Teach your kids about their different properties, and how they were used to make hand tools.
Then, the different properties of woods. Hard, soft, green, etc. Show them why ash and hickory (and especially negatively buoyant cornus mas, if you can get it,) make much better tools than pine. Make wooden spears and harden their points in a fire you make with stone tools.
Then integrate the two -- use stone tools to make other stone tools, and combine stone and wood into wooden-handled stone tools. Make bows and stone-tipped arrows, and use them. Go foraging with the children, and teach them how to cook vegetables, fish, and meat over an open fire. (Note: Beware mushrooms unless you really know what you're doing.)
In short order, the children will understand how men have lived for hundreds of thousands of years. Then they can advance into copper smelting, pottery, building carts and canoes, making nets from natural fibers, writing on clay tablets, and so forth...
I feel that, as with math where the optimal method is to start with Euclid and then progress through the ages, one ought to learn to be in the world by moving through man's stages of development. At 4-7, they're in their prime for traipsing around the woods and making stone tools.
And this paves the way to the rabbit hole of fossil collecting. And easily to camping, star gazing, Astronomy, Physics, Math and all sorts of things that humans naturally need in the wilderness.
I live in a pretty rural place, and around here they sell wild mushrooms in supermarkets. Sometimes the mighty porcini (boletus sp.) is available -- but there are frequently chanterelles and morels available, and sometimes other types. Kids and even toddlers eat them all the time, though admittedly they're usually well cooked, or dried and then cooked, or even cooked and then pureed.
I don't recommend doing it with kids (or at least eating them with kids) but mushroom foraging is a lot of fun.
You start with the different properties of stones. If you have flint, obsidian, granite, quartzite, gypsum, and calcite in your region -- find them together. If not, buy them. Teach your kids about their different properties, and how they were used to make hand tools.
Then, the different properties of woods. Hard, soft, green, etc. Show them why ash and hickory (and especially negatively buoyant cornus mas, if you can get it,) make much better tools than pine. Make wooden spears and harden their points in a fire you make with stone tools.
Then integrate the two -- use stone tools to make other stone tools, and combine stone and wood into wooden-handled stone tools. Make bows and stone-tipped arrows, and use them. Go foraging with the children, and teach them how to cook vegetables, fish, and meat over an open fire. (Note: Beware mushrooms unless you really know what you're doing.)
In short order, the children will understand how men have lived for hundreds of thousands of years. Then they can advance into copper smelting, pottery, building carts and canoes, making nets from natural fibers, writing on clay tablets, and so forth...
I feel that, as with math where the optimal method is to start with Euclid and then progress through the ages, one ought to learn to be in the world by moving through man's stages of development. At 4-7, they're in their prime for traipsing around the woods and making stone tools.