I wonder why you are so insecure that you feel you must try to insult everyone in every sentence.
Do you mean approximating? Could just round it up so it's divisible by ten and remove the excess but it's not the answer. Calculating the limits I.e 164*1,6 took more time.
Besides, I can't fathom why everyone should have to convert everything by themselves, this would be the effect of the suggestion. It would be the absolute most needless, time wasting, and unnecessary effort society could do.