400 years ago lead was harnessed to wood and thus pencils were born! Today, most pencils are made of graphite surrounded by a wooden shell. The average pencil can draw a line for about 35 miles! If you're not drawing 35 mile long lines you could be writing words, about 45,000 words is the average life span of a graphite pencil. This prolific writing tool is used all over the planet so it’s no surprise that about 15 billion pencils are manufactured every year! That's enough to reach (end to end) from Earth to the moon seven times. Also, seeing as how pencils work in zero gravity, they're often used for space missions over standard pens. This impressive tool has been used by such great minds as Thomas Edison, John Steinbeck, and Johnny Carson! Remember to use a sharpener because writing with a broken pencil is...pointless!