Numbers, Numerals and Digits
This is little Lucy. She loves to play with a ball. But she doesn't really have a ball at the moment - she's thinking
of the ball, so she has the idea of a ball in her mind. In fact, she has the idea of one
ball in her mind, and she wants to chase it!
Numbers are ideas too. They're the ideas we use to count things or measure them. We might count Lucy's ball with the number
one, but it is really just an idea in our minds.
If we want to talk or write about numbers, rather than just thinking of them, we need to use numerals such as "1" or "one". But
we could also hold up 1 finger, or tap on the ground with our foot once in the same way that some dogs have been trained to "count". Lucy might
thump her tail against the couch once if she was as clever as we like to pretend she is.
There are many different ways of referring to the same number. All numbers have names or symbols that we call
numerals. Some numbers like \(\pi\) ("Pi") can't be written down exactly in decimal format, but we still have the idea of what "Pi" means,
so it is still a number.
Numerals are the names or symbols that we use to refer to numbers when we are talking or writing about them.
For example: 17, 253 and seven are all numerals.
Just like words are made up of letters,
digits are the symbols that make up numerals.
Our everyday numerals are made up of the ten digits:
For example: The numeral \(867\) is made up of the 3 digits "8","6" and "7".
For example: The numeral \(29\) is made up of the 2 digits "2" and "9".
For example: The numeral \(3\) is made up of the single digit "3".
For example: The numeral \(867,389,272\) is made up of the 9 digits "8","6","7","3","8","9","2","7" and "2".
You can use digits to build numerals that are as long as you like! The numbers keep going on forever and ever, and so do the numerals that we use to write them.
The Connection Between Digits, Numerals and Numbers
We know that letters make up words and words are used to describe the idea of something:
Well, the same sort of thing happens with digits, numerals and numbers. Digits make up numerals and numerals are used
to describe the idea of a number.
Getting the words confused
Everyone gets mixed up and says "Number" when they really mean "Numeral". It really doesn't matter because people will understand
what you mean. The important thing to get right is to use "digit" only to refer to the symbols that make up numerals.
Other Types of Digits and Numerals
There are lots of different ways of writing numerals. The ancient Babylonians used a stylus to make wedges in clay
tablets, the ancient Egyptians used hieroglyphic symbols for their digits and the Romans used Roman Numerals.
Why not search the internet and see if you can find some other different numbering systems? There are heaps of them!