# Percentage nature [closed]

In mathematical expressions, the internationally recognized symbol % (percent) may be used with the SI to represent the number 0.01. Thus, it can be used to express the values of dimensionless quantities. According to Le Système international d’unités/The International System of Units, (Brochure sur le SI/SI brochure), 2006.

In mathematics, a percentage is a number or ratio expressed as a fraction of 100. It is often denoted using the percent sign, "%", or the abbreviations "pct.", "pct"; sometimes the abbreviation "pc" is also used. A percentage is a dimensionless number (pure number). Based on Wikipedia, https://en.wikipedia.org/wiki/Percentage

Is percentage considered as a number?, e.i. can I add a number to percentage?

Which is correct

30+10%=30.1

or

30+10%=33

• This question doesn't seem to be about teaching mathematics and it would be more appropriate to ask at math.stackexchange.com Dec 19, 2016 at 9:22
• @AmyB, I already asked it there, my intention to post it here is to know educators' perspective when they teach something like this. Dec 19, 2016 at 11:30
• To those voting to close this question, the OP originally posted it at Mathematics Stack Exchange and I suggested that he repost it here, hoping that it would get a better reception.
– JRN
Dec 19, 2016 at 13:04
• Ali Tarek, if you are interested in how mathematics educators translate the expression $30+10\%$, consider editing your question to something like "Is the addition of pure numbers with percentages taught in school? If so, then how is it to be interpreted?"
– JRN
Dec 19, 2016 at 13:07
• I would take 30 + 10% to be an informal shorthand for 110% of 30 or $1.10 \times 30 = 33$. Dec 20, 2016 at 15:29

Percentage means exactly as you say. 1% = 0.01. It has a few versions: https://en.wikipedia.org/wiki/Percent_sign , permille ‰ is often used for alcohol content in blood. The per-cent means per hundred and per-mille per thousand. Because it is a shortening, it requires always a number front of it. % + % * 5 + %$^2$, would not be acceptable.