How does that old song go again? The knee bone's connected to the…? Shin bone? Thigh bone? Both? Aarrgghh! We can't remember.

Anyway, we were WONDERing about bones the other day and wanted to know how many we had. We tried to count them, but then we realized they're all under our skin! It would be much easier if we had see-through skin or a best friend who was just a skeleton.

Do you have any idea how many bones you have? Did you realize that the number of bones you have changes from when you're a baby to when you're grown up? It's true!

Babies start out with over 300 bones. Since babies have a lot of growing to do, some of the bones they'll have as adults start out in multiple pieces. Over time, these bones grow together to form one larger bone.

By the time you're an adult, you'll have exactly 206 bones. Over half of those bones can be found in your hands and feet! Your bones can be divided into two skeletal systems.

The axial skeleton contains all the bones in the trunk of your body (that's the middle part of your body that includes your spine). The appendicular skeleton contains all the bones in your limbs (that includes your arms, hands, legs and feet).

Bones can be further classified into four categories. Short bones are, of course, short, and they help strengthen your skeleton. Long bones are — surprise! — long, and found in your limbs. Flat bones protect your organs and provide a spot for muscles to attach. Irregular bones are oddly-shaped bones that don't fit into any of the other categories.

You would look really funny without bones. Can you imagine being just a big pile of skin? It would be hard to do anything! Your skeleton gives your body shape, helps you move, protects your body, stores minerals, and helps to produce new blood cells.

It's important to take care of your bones and keep them healthy. Obviously, you can't take them out to inspect or clean, so how should you take care of them? Your bones are alive and, like all other living things, they need proper nourishment.

For example, you can help keep your bones healthy by making sure you get enough calcium. Calcium is a mineral that helps bones harden and become strong. Foods with calcium include dairy products, such as milk, cheese, and yogurt.

You can also keep your bones healthy by exercising. If you play sports, though, make sure that you protect your bones by wearing the proper safety equipment, including helmets and pads!

Wonder What's Next?

Tomorrow’s Wonder of the Day is sound asleep…or is it?