largest and small bones
The biggest bone in the human body is the thigh bone, or femur. In an average man, it is about 45 cm (18 in) long. The end of a thigh bone contain lots of small spaces filled with marrow cells, which help to save weight. Without these space, moving about would be hard work because the bone would be very heavy.
The smallest bone is the stirrup, inside the ear. It is just 5 mm (1/5 in) long and helps to carry sounds into the inner part of the ear. There are three bones in each ear, and they are so small that they would all fit inside a matchbox.

In an adult, the thigh bone can weigh over 200 000 times as much as the stirrup bone hidden away in the inner ear.

How many bones are there in my body?
It dependshow old you are. At birth, a lot of the skeleton is made of a rubbery substance called cartilages. As you grow older, most of this turns to bone. Then some bones start to join up. For example, two bones that form your forehead grow together soon after birth. In your mid-teens, five bones near the base of your spine start to form a single bone called the sacrum. By your mid-twenties, you will have about 206 bones.