How to use the percent button on a calculator

If you have a percent button in your calculator you might be wondering how to use it or what is it used for?!
Percent in calculators used to quickly figure things like the price of items on sale, calculate tax ... etc

So how percent on Calculators function?

This is tricky, because unlike other operators like (+ , - , ×, ÷), percent doesn't always behave the same, it depends on the pervious operator.  let me show you different scenarios

Case 1: Percent after '+' operator

This add percent to the original number, for example suppose you want to compute how much a $80 t-shirt will cost after including 5% tax 
The answer is $84 which is correct since 5 percent of 85 = 4 adding it to 85 results 84

Case 2: Percent after '-' operator

Suppose the same t-shirt is on sale and it's price is off by 20%, in this case we use the - operator
80 - 20 %
Captured using Calculator+ by xNeat
The answer is $64, because 20 percent of 80 is 16, subtracting it from 80 the result is 64

Case 3: Percent with '-' and '+' operators

Now we have a t-shirt that cost $80, and is on sale 20% off, with 5% sales tax
We calculate 80 - 20% + 5%
80 - 20% + 5%
Captured using Calculator+ by xNeat
The answer is $67.2 since 20% of 80 = 64, then we add 5% to get 67.2, in this case the order doesn't matter, '80 + 5% - 20%' will give us the same result

Case 4: Percent with '×' operators

Suppose we want to know how much we save by buying a $80 t-shirt that is on sale 20% off.

We calculate 80 × 20%
80 - 20% + 5%
Captured using Calculator+ by xNeat

The result is 16, which is correct since 80 × 0.2 = 16

Case 5: Percent with '÷' operators

This one is barely used,  80 ÷ 20% is equivalent to '80 x (1/0.2)'
So to sum things up, use % with '-' for sales, % with '+' for taxes!
You are ready now to take the percent button on your calculator to the next level!


If you want a percent calculator for your iPhone that preserve the order of operation, you can give Calculator+ by xNeat a try, it's FREE, download it from the App Store. 






Best Calculators for Apple Watch


Having a Calculator on your Apple Watch is must, you can easily calculate discounts and sale prices on the spot without the need to take out your iPhone from your bag or pocket, however selecting the best calculator is quite challenging giving the varieties of calculators already exist in the App Store.


So let's first start by listing, what do we really need from our calculator on Apple Watch?


Firstly, big buttons & font, we are speaking about a tiny screen here, having all the functionality on one screen might not be the smartest thing to have!
Secondly,  all the basic operations must be easily operated especially the '+', the '-' and the '%' if you used to it like me
Thirdly, being stylish is a plus!

Now after listing down what we need, let's check out this Free nifty Calculator+ by xNeat. 

download it from this link


When you open Calculator+ on Apple Watch, we see a nicely placed black numbers. Using a neutral black color for the buttons is a good choice as it blends the Calculator with the Apple Watch frame as well with different bands' color offered by Apple.

Basic Calculation Operation on Apple Watch
Enough talking, let's explore it!

How to calculate basic operations like '3 + 4 ='? 

This operation takes 4 steps:

  • 1. Tap '3'
  • 2. Swipe right (for what is called Fast Plus)
  • 3. Click '4'
  • 4. Swipe right (for the result)
Actually this isn't bad at all, since this usually takes 4 taps on regular calculator, here it takes us 2 taps and 2 swipe!

Complex Calculation Operation on Apple Watch


What about relatively complex operations like '3 + 4 % ='?

It takes 6 steps:

  • 1. Tap '3'
  • 2. Swipe right
  • 3. Tap '4'
  • 4. Tap 'more'
  • 5. Tap '%'
  • 6. Swipe right (for the result)
This percentage operation takes 5 steps on regular calculators, here it takes us 6 steps, which isn't bad actually given the compromises need to be taken to keep the balance between usability and functionality on the small Apple Watch screen.


Calculator+ by xNeat comes with a set of predefined themes to match the different colored bands offered by Apple.

Calculator+ themes for Apple Watch

Calculator+ contains a set of extra features, that is nice to have as copy & paste, saving the answer, brackets for more complex operations and more!