- Most people can generally hold around seven numbers in their working memory for a short period of time (Miller’s law), which explains why our telephone numbers are mostly seven digits (excluding the country and area codes).
- Several sleep studies have found that seven hours is the optimal amount of sleep, not eight!
- There are seven colours in the rainbow: red, orange, yellow, green, blue, indigo, and violet.
- The ‘Seven Seas’ (as in the idiom ‘sail the Seven Seas’) is an ancient phrase for all the world’s oceans: Arctic, North Atlantic, South Atlantic, Indian, North Pacific, South Pacific, and Southern (or Antarctic).
- There are seven continents in the world: Africa, Europe, Asia, North America, South America, Antarctica,and Australia.
- Seven is used 735 times in the bible (54 times in ‘Revelation’ alone)! If we include ‘sevenfold’ and ‘seventh’, the number jumps to 860!
- And of course, seven is a prime number. 😉
Happy Seven! 😀
Sponge ME, Maths Tuition (Singapore)