Information

You know, humans don't often seem to ask themselves why they need numbers.

It seems quite obvious.

They need to know 'how many',

and to know whether things are more or less,

or bigger or smaller than each other,

and how much so.

And they know that they can let someone else know

that they mean the number three by holding up three fingers.

But you quickly run out of fingers if you are trying to count sheep in a field,

so they had to find some kind of signs to show how many they meant when they were counting lots of things.

If they could count how many sheep they had, they could tell if any sheep were missing.

So they started making marks in mud for every number they counted, like the dots on dice or dominoes,

you just look at the dots and you know the number.

But for big numbers with a lot of dots, that didn't work too well, so to make it easier they put the numbers into groups.

They might make groups of five, to match the fingers of one hand by making four lines counting to four, and then one across to make it five.

Then they decided to group things in tens, to match the number of fingers on both hands,

and that was easy enough to work with if they used an abacus, but much harder to write down.

So they came up with written signs for the numbers,

and they called them digits, the same word they used for fingers,

and they wrote out big numbers by moving the digits over a place when they reached a ten,

and if there were no units to go with the ten they marked the place that was left with a zero.

And suddenly it became so much easier to add and subtract and multiply and divide.

But sometimes you don't need an exact number for an answer.

If you want to know which of two people is taller, you don't have to measure them,

it's easier if you just stand them side by side.

And sometimes it's the same with much more complicated things.

You need to collect the information in numbers, but find ways to organise it in the best way to make it useful to tell you what you want to know.

And they do that by displaying it in different ways to make it easier to see and understand what the numbers mean.

You can have the same numbers but show them and look at them in different ways.

So they will use tables to show the days and times that shops will open,

or list the times of buses and trains in timetables.

And of course, muslims use timetables to keep track of daily changes in the times of Sala.

And they use graphs and charts to compare things with each other or over time.

And they use the numbers as data so that they can see how lots of things move and change together.

You don't have to know every detail to be able to see the bigger picture.

Sometimes you don't need an exact number, you just have to be close.

But it's useful to know just how close you are,

if it's very close, or just a wild guess.

What are the chances?

Understanding what numbers say

Finding the best guess