Anything that involves percentages.
In: Mathematics
Percent is just short for a Latin phrase for “per hundred”. The “cent” in percent is the same cent as the cent that is one hundredth of a dollar or the centimeter that is one hundredth of a meter.
The percent sign comes from a way to write “x/100” very fast very often.
1% is 1 out of 100 or 1/100 or 0.01
2% is 2 out of 100 or 2/100 or 0.02
3% is 3 out of 100 or 3/100 or 0.03
10% is 10 out of 100 or 10/100 or 0.10
50% is half of the whole or 0.5
100% is a whole or simply 1
If you say 1% of a the population you mean one out of a hundred people.
An important thing to keep in mind is that adding and subtracting percentages is not something you can do in any order.
If you normally add and subtract numbers together it doesn’t matter what order you do it in 5 + 3 – 2 is the same as 5 – 2 + 3.
Withe percentages this matters because you always base percentage on current whole.
A Discount of 25% on something that already was 50% of is different than a discount of 50% on something that was 25% off.
Reducing something by 30% and than increasing that by 30% will not get you to where you where you started out.
Also sometimes when you owe money or are investing money you end up in places where cumulative interest is a thing. You may get something like 5% interest every year, but that doesn’t mean that after 5 years you have 25% more than you started with but instead something closer to 27.6% because each year you added 5% of something that was already 5% bigger.
For most things you can just write it out as a decimal number or a fraction and get the same result.
Latest Answers