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Numbers have always been important, but throughout the ages some
numbers have been considered more special than others because of
what they signify to different people or civilisations. Sometimes
the reasons for a number being 'lucky' or 'special' are based on
its mathematical properties, for example see Pi, a Very
and Can You Find
a Perfect Number?
Sometimes a number is thought of as lucky because it happens to
relate to something else that people think is important. Number 8
is lucky in Chinese culture because the Chinese word for "eight"
sounds like the word for "wealth". Some people choose their lucky
number because it is the shirt number of their favourite sports
player. There are many different ways in which a number can be
special. Do you have a lucky number? Why is it special to
Two of my favourite numbers are 5 and 7, because they crop up all
over the place in nature, history, literature, films and even pop
groups! They are both prime numbers too, which makes them even more
Five is an interesting number because it occurs a lot in nature.
Humans have five senses (sight, smell, taste, touch and hearing)
and five fingers on each hand. There are some fascinating creatures
like starfish that have five-fold symmetry, that means you can
rotate them five times and they will still look the same:
Starfish picture by Tom Trinko
The Ancient Greeks believed that everything in the universe
was made of five elements:earth, water, fire, air and quintessence
which was supposed to be what the heavens were made of. Five is
also the number of Platonic Solids that are possible. These are the
only 3-dimensional shapes that are completely regular, which means
that all their faces are the same size and all their edges are the
same length. Find out more about the Platonic solids, and how to
make them here
Seven is another fascinating number. There were seven wonders of
the ancient world, amazing man-made structures of which only one
survives today - the Great Pyramid of Giza in Egypt. To find out
The city of Rome was built on seven hills, as were several other
cities including Moscow in Russia, Jerusalem in Israel and
Sheffield in the UK.
In music there are seven different notes in a harmonic octave (the
top note is the same as the bottom one but an octave higher). There
are also seven traditional colours of the rainbow. This is no
coincidence, in fact it was Isaac Newton who decided that the
rainbow should be split into seven colours to match the musical
"And possibly colour may be
distinguished into its principle degrees, Red, Orange, Green, Blew,
Indigo,and deep Violet on the same ground, that sound within an
eighth is graduated into tones."
So you see, spotting numerical connections between things has been
a popular activity for centuries. There are actually an infinite
number of different colours, but seven is easier to remember.
Now it's your turn!
See how many things you can think of that correspond to your
favourite number. If you picked one of the numbers above, try to
think of some more things that aren't mentioned here. For example,
there are 5 players in a basketball team.... what else can you
think of? Next try starting from one and counting upwards. For each
number, think of a reason why it is special. How far can you get
before you find a number that isn't special? Here are some ideas we
thought of, but can you think of different reasons why each of
these numbers is special? Try to vary it a bit so that you don't
just have your top 20 football players or something like
1 is the only number that is the square of itself
2 is the only even prime number
3 is the number of books in a trilogy, like Lord of the Rings
4 is the number of musicians in a string quartet
5 is the number of 'pillars' in the Islamic religion
6 is the number of faces on standard dice
7 is the number of days of the week
8 is the luckiest number in Chinese culture
And so on.... Give it a try and see how far you get. You could even
try setting some maths problems for your friends using clues
instead of numbers. The possibilities are endless!
Penelope Gouk, "The Harmonic Roots of Newtonian Science," in Let
Newton Be! ed. John Fauvel et al. Oxford: Oxford University Press,
1988, pp. 101-126. Quotation from p.118.