numbers

The average adult has about 100,000 hairs on their scalp, with the exact number depending largely on natural hair colour.

An average human heart beats roughly 2.5 to 3 billion times over a lifetime of about 80 years.

There is no exact figure, but the Oxford English Dictionary contains over 500,000 words and senses, and estimates of all English words reach about a million.

There are eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune; Pluto was reclassified as a dwarf planet in 2006.

Astronomers estimate the observable universe contains roughly 100 billion to 2 trillion galaxies, with most recent estimates in the hundreds of billions.

About 2 million species have been named, but scientists estimate there may be around 8.7 million species of plants and animals, and far more if microbes are included.

A 2015 study estimated there are about 3 trillion trees on Earth, roughly 400 for every person.

A 2022 study estimated there are about 20 quadrillion ants on Earth — roughly 2.5 million for every person.

The ISS orbits Earth at about 28,000 km/h, circling the planet roughly every 90 minutes.

There are five named oceans: the Pacific, Atlantic, Indian, Southern and Arctic, though they all connect as one global ocean.

The most common answer is seven: Asia, Africa, North America, South America, Antarctica, Europe and Australia, but some countries teach five or six.