Now almost no one counts in their minds or on a piece of paper, especially when it is necessary not only to add numbers, but to perform more complex calculations, for example, add percentages to a number. It is much easier to do this with a calculator.
How to add percentages to the number: theory and practice
There are often times in life when it is necessary to add percentages to a number. For example, to calculate how much we will receive at the end of the deposit in the bank.
It is known from the school mathematics course: to add any percentage to a number, you need to use the formula: K + K * (b / 100), where K is a number and b is a percentage. First of all, you need to calculate the percentage of the number K, then express the percentage as a fraction and multiply the fraction by the number. Then add the number with the percentage.
For example, there is a product worth 1,500 rubles, but this cost must be increased by 20% (the amount of value added tax). According to the formula K - 1500, b - 20%. The calculation will look like this: 1500 + 1500 * (20/100) = 1800.
The amount of goods with tax is 1800 rubles.
This is hard to do in your head, especially if the numbers are large. Therefore, a calculator comes to the rescue. There are a lot of models of this device: from the simplest to specialized. The latter, as a rule, are used in narrow areas (medicine, science, etc.). Nowadays, simple calculators are found in almost all cell phones.
How to add percentages to a number using a calculator
In order not to make mistakes and not to press the wrong buttons, carefully read the calculator. Follow the simplest steps, for example, 2 + 2. After that, you can safely proceed to more complex calculations. In our case, adding to the number of percent.
Let's look at the same example. Add 20% to 1500. We type the number 1500 on the calculator, press the addition button "+", dial 20 and the button "%". There is no need to type "=", the desired answer will be displayed on the scoreboard immediately.
So, the algorithm: enter the original number, press the addition key (+), specify the percentage and type the "%" icon.
If, for some reason, there is no "%" button on the calculator or it does not work, then the calculations will be more difficult, you will have to use the same school formula: K + K * (b / 100). That is, it will be necessary to perform the following actions: in our case, dial 20, the division key "÷", then the number 100, the "=" key, the multiplication symbol "*", the number 1500 and again "=". Add the resulting number to 1500 and finish with the "=" button. You will have to make more efforts, but it's still better than counting in your head.
It also happens that a lot of calculations need to be made and, in order not to memorize or write down intermediate results, you can use the MS, MR and M + buttons.
MS records the number on the scoreboard into memory. If the calculator does not have such a button, then “M +” is used instead. And when both buttons are present on your device, then M + is used to add a number to the result recorded earlier. MR simply prints the number from memory onto the calculator scoreboard.
Of course, calculators have greatly simplified our life, but still, in order not to forget how to count, sometimes do calculations in your head.
