Adding numbers in appropriate ranges

Without further clarification it's hard to answer your question, so I'll take a shot in the dark.

Let's say the number you're assessing is in A1.
=CEILING(A1,10)/10

Westu7 

You need to do a lot of clarifying if you really want to get help. 

"add the right number of numbers"

What is the "right number of numbers" in the "example" you first posted? 

"when a certain range is exceeded"

What does "a certain range" refer to? A range of numbers--the numbers themselves--or a range or cells containing numbers? Or something else?

For example,

=< 10 +1, =< 20 +2, etc.

The "=<" would mean "up to or equal to" which doesn't go along with "a range being exceeded" so how is one supposed to interpret that? If you really wanted to mean "equal to or greater than" you'd represent that by ">=" or "=>"

And if the "exceeded range" is greater than 10, is 1 the number to be added? Literally 1, or one number? One random number?

It is supposed to happen after receiving the truth in the chosen cell.

I think the "it" that is supposed to happen will be taken care of by your answers to the preceding questions, but how will the truth be recognized? How are we to know what "the chosen cell" is? 

IF you have a workbook already created that contains the range, the cell that will receive the truth, etc., it would actually help us help you if you were to post a copy of that workbook on OneDrive or GoogleDrive and then post a link here granting editing access to said workbook.

But please, do clarify what the functionality is that you're seeking.