How do you translate "18 more than a number" into a mathematical expression?
So in this instance, whenever we come across the wording "a number", we can and may use the letter
This is because we may assign to
The question uses the word 'expression'. This means that there is not an equals sign in what we write.
I use the symbol ? to indicate that something should be in that place. We just do not know what is yet. It will show up later.
Breaking the question down into its component parts:
18 more than:
So we start with some unknown value and put a further 18 with it. So it becomes more.
Hope this helps