We looked at numbers on previous page where covered all the numbers we use in everyday life (1, 2, 3, 4 …) which are the natural or counting numbers (N) and expanded this all the way down to the vast majority of the world of maths uses (negatives and zero that make up the whole or integers, fractions, irrational numbers like pi and square root of 2 (√2)) termed real numbers (R). We even had a quick look at the weird but beautiful world where imaginary and complex live (C). On this basis we can now look at the things we do to these numbers notably the whole numbers or integers (…, -3, -2, -1, 0, 1, 2, 3, …).

For clarity I’ll be using the more precise term of integer instead of number but just remember I’m talking about whole numbers that you see and deal with every day.

Factors – building up and breaking down numbers

You may remember factors from school as they are a key part of fundamental maths. The factors on an integer are those integers that when multiplied together produce that number. By this definition the integer 1 is a factor of every number plus the integer itself. If there are only 2 integers (1 and itself) then the number is a prime number (e.g. 1, 2, 7, 19, 29, … 859, …). The definition also excludes fractions so no multiplying by a half.

But the question you may not have asked is why do we need to know factors? Who cares? I have a calculator on my phone/watch/computer/table so I don’t need to be able know what factors make up a big number.

An excellent question.