People are great at using and understanding numbers between one and ten but scientists often need to use much larger quantities.
- The speed of light is 300,000,000 metres per second.
- The distance to the moon is 384,467 kilometres.
- There are usually between 10,000,000 and 20,000,000 sperm per millilitre of human sperm.
Big numbers like these can get confusing.
- One thousand 1,000
- One million 1,000,000
- One billion 1,000,000,000
- One trillion 1,000,000,000,000
Some of these numbers are truly huge, think about them as measures of time:
- One thousand seconds is nearly 17 minutes
- One million seconds is 11½ days
- One billion seconds is nearly 32 years
- One trillion seconds is nearly 31,710 years
Things can get worse, there are around 8,360,000,000,000,000,000,000,000 molecules in a cup of tea!
Going to the other extreme very small numbers are used by scientists just as often.
- These marine diatoms (seen here through a microscope) range in size from ten to 150 millionths of a metre. That is from 0.00001m to 0.00015m.
- The wavelength of the blue light coming from this image is about 450 nanometres (nm) - 0.00000045m.