1decametre (dam) =

1 kilometre (km) = 

1 centimeter (cm) = 

1 hectometre (hm) = 

1 fermi = 

1 Å = 

1 Pico metre (pm) = 

1 nanometre (nm) = 

_____ is to measure short distances such as length of the book.

_____ is used to measure very small length such as thickness of a coin.