Well, you would start with the negative (-) numbers.
-20,-13,-9.
I put -20 first because it is the smallest. Not to say that 20 is a small number but, when it's negative the value goes down. -9 would be the biggest out of the negative numbers.
-20, -13, -9, 7, 15, 20
That's the completed line of numbers from ltg.
As you should know 7 is a small number because it's positive. Although, it is not the smallest out of the whole number set. In the whole number set, the biggest number is 20.
I will repeat the complete number set now: -20, -13, -9, 7, 15, 20.
I hope this helps!!