It’s really irritating how people use negative integers (or real numbers) in place and out of place. I feel they don’t even know the difference between, let’s say 10% and -10% of the value of some product. It can be very amusing – when it needs to be told how warm or cold is it outside, nobody thinks – 10 degrees are the same as just 10 degrees 
However, when it comes to prices and discounts of prices, everyone goes mad:
Q: How much is that TV set?
A: It’s usually, $ 200.00, but now it has a discount of -10%..
So if it has a discount, it means you have to subtract the amount of the discount from the original value to get the new value, right? So, 200-(-10% of 200) = 200-(-0.1*200) = 200-(-20) = 200+20 = 220. Hip, hip, hurray, the new price after applying the discount is $ 220.00! J And what’s even funnier, it’s not just about the average person inhabiting the world of ours, it’s even more about all the companies and enterprises putting those “Sale! All the merchandise’s having a discount of -20%” labels in their windows. Could somebody, please, teach them a bit of math? You can say either of the following, but, please, don’t mix them together:
- all the merchandise has a discount of 20%;
- the new value of all the merchandise is -20%
P.S. This is my 17th post in this blog, so let’s remember that thought about 17 being an evil number!
As I have seen, banners usually just show “10% off”. Interpretate how you like.
`10% off` ir perfectly OK. The thing is not always it is said in this manner.. moreover, not even usually, as I have noticed..
[...] brinkley wrote an interesting post today!.Here’s a quick excerptA: It’s usually, $ 200.00, but now it has -10% discount.. So if it has a discount, it means you have to subtract the amount of the discount from the original value to get the new value, right? So, 200-(-10% of 200) = 200-(-0.1*200) … [...]