Learning about percentages doesn’t have to be complicated. You will learn a step-by-step method to calculate any percentage on paper without making mistakes, and you’ll master some incredible tricks to perform these calculations in your head in just 5 seconds. Welcome.

What Does Percentage Mean? The Concept Behind the % Symbol

Before diving into the calculations, grasp the concept: the percentage symbol simply means “per cent”—that is, divided by 100. Any percentage can be expressed in three ways: as a percentage, as a fraction over 100, or as a decimal. Understanding this is the key to avoiding getting stuck when performing calculations.

Example – Representations of 25%:

Percentage Form

Fractional Form

Decimal Form

Method 1 – How to Calculate Percentages on Paper (A Step-by-Step Guide)

How much is 15% of 80?

Let’s put this into practice on paper. How do you calculate 15% of 80? The rule is:

• First, you multiply the numbers.
• And then divide by 100.

15% of 80 = 12

Method 2 – The “Zero-Cutting” Shortcut. Saving Time on Paper.

How much is 30% of 20?

Want to speed things up when working on paper? Whenever numbers end in zero, you can drop the zeros before multiplying. To calculate 30% of 20, simply remove the zero from both 30 and 20. The calculation then becomes just 3 times 2, which equals 6. Quick and error-free.

Method 3 – The Reversal Trick (A% of B = B% of A)

How much is 8% of 50?

Here’s a trick not many people share: the order of the numbers doesn’t change the percentage! If someone asks you for 8% of 50, the calculation might seem annoying. But just flip it in your head: what is 50% of 8? 50% is half! Half of 8 is 4. Therefore, 8% of 50 is 4. Pretty impressive, right?

Video Lesson – Percentage

Check out my video lesson, where I explain all this content in a simple way that you’ll grasp in no time.

Exercises with Annotated Solutions – Click here

Happy studying! See you next time!
Professor Silvio