Finding the percentage of a certain number is exactly the same as calculating a percentage. It is very common to say that you must calculate the percentage of something to pay, collect, distribute, and knowing how to do it is very simple and practical. You can do it by applying the proportions you learned in school, the simple rule of three, or simply a multiplication.
The percentage can be raised in different ways, for example can we say what percentage represents 5 of 10? The answer is easy, it is half, and half of something expressed as a percentage is 50%.
We can also ask ourselves how much is 15% of 700? This, for example, can happen if they tell us that we get 15% of €700. We’ll see how to calculate it.
Another example in which we apply percentages or percentages : if 65% of a number is 40, then what is that number? We will also see how to solve it.
We will explain how to calculate a percentage and that you know how to apply it to any problematic situation of daily life that comes your way.
What do you need to calculate a percentage?
- Pencil and paper.
- Calculator.
Instructions to calculate a percentage
- The percentage or percentage is generally widely used in statistics that are then represented for better interpretation in different types of graphs. Other times they are used to solve a specific problem such as a discount, surcharge, partitions, etc.
- When they tell us that a count of cars has been done on a corner for a whole day and it resulted, among others, that 6 out of 20 cars are black, what percentage does that represent? In this case we don’t even know what the total number of cars is, it is simply a statistic that can be represented as a percentage.
- It is considered as a division: 6/20 and it reads six out of twenty, if we do the division it will give us 0.3 and if we multiply this number by 100 we will obtain the percentage: 30%. In other words, if we hear that 6 out of 20 cars that pass through a certain place are black, we can also say it in the following way: 30% of the cars that pass through here are black.
- Let’s solve the problem raised above, if we are going to receive 15% of €700, how much money will it be?
- The total, that is, 100% is €700, so 15% will be a part of the €700. How do we calculate it? Simply by a proportion: 100% corresponds to €700. Therefore, 15% will correspond to Let’s see how it is written and how the calculation is solved:
- Another case of percentage is when we know the number that represents a percentage but we do not know what the number is: If we know that 65% of a number is 40, what we should find is 100%. In this case we consider 65% corresponds to 40, so 100% will be x, logically a number greater than 40.
- Indeed, the number whose 65% is 40 is the number 61.54, that is, if we took 65% out of 61.54, it would give us 40(approximately).
- We can calculate percentages directly with the calculator. All calculators have the % key that allows us to use it to calculate a percentage. To use it you must first write the number from which you want to get the percentage, suppose you want to calculate 8% of 205, first you write 205, then the x key (multiplication), then 8 and finally %, finally So you will get 16.4 which is 8% of 205.
- You can also calculate the percentage of surcharges or discounts directly with the calculator.
- For this, you first calculate the percentage you want to calculate and then press the + sign if you want to calculate a surcharge or the minus sign if it is a discount, directly obtaining the final result with surcharge or discount.
- For example: A refrigerator costs €200. If you buy it in cash, they discount 7%, but if you buy it in three installments, they charge you a total 12% surcharge. Let’s calculate with the calculator doing the following sequence:
- Discount: 200 x 7% –= € 186, that is, if you pay in cash you will have a reduction and you will pay €186
- Surcharge: 200 x 12% + = €224, that is, if you buy it in installments you will pay €224
- Check these results by calculating the percentages and adding or subtracting the price of the refrigerator to see if they match.
Tips for calculating a percentage
- Practice calculating percentages using a calculator, in your head, and with pencil and paper as hand calculations are necessary to keep your brain active.
- Be careful because different calculators work differently, in the example you have a way to calculate percentages but always check how it works to be sure when doing simple calculations: for example, calculate 50% of a number that you already know will give you half.