1. When you do numbers in math, and say 1 + 1 equals 2, is the 2 actually 2 units of precisely the same size, or does the quantity within the numbers augment as you go? When you count, are the units in 3 all equal, or is it trickier than that?
2. why did the dinosaurs die? And are we sure they all did?
3. why do they ask questions about apples and oranges being in the same barrel in my arithmetic book? Everybody knows oranges spoil really fast, but apples will last for a long time if you keep them cool, and everybody knows if you put rotten fruit up against good fruit, the good fruit is apt to start rotting sooner. So the answer to how many apples and how many oranges in the barrel is “No oranges if you don’t sell them real fast, and a lot fewer apples than you would have had if you’d stored them properly in their own barrel.”
4. where do shooting stars come from?
5. what makes lightning bugs glow?
6. how does grandma’s crank phone work?
7. why can pigs eat dirt and not get sick?
8. why do rainbows move when you chase them?
9. why does it rain?
10. where did all the water in the oceans come from?

Oddly enough, some are still real good questions.