Many people wonder how to round numbers. This need often arises for people who connect their lives with accounting or other activities that require calculations. Rounding can be done to integers, tenths, and so on. And you need to know how to do it correctly so that the calculations are more or less accurate.
What is a round number? It's the one that ends in 0 (for the most part). In everyday life, the ability to round numbers greatly facilitates shopping trips. Standing at the checkout, you can roughly estimate the total cost of purchases, compare how much a kilogram of the same product costs in packages of different weights. With numbers reduced to a convenient form, it is easier to make mental calculations without resorting to the help of a calculator.
Why are numbers rounded up?
A person tends to round any numbers in cases where more simplified operations need to be performed. For example, a melon weighs 3,150 kilograms. When a person tells his friends about how many grams a southern fruit has, he may be considered not a very interesting interlocutor. Phrases like "So I bought a three-kilogram melon" sound much more concise without delving into all sorts of unnecessary details.
Interestingly, even in science there is no need to always deal with the most accurate numbers. And if we are talking about periodic infinite fractions that have the form 3, 33333333 … 3, then this becomes impossible. Therefore, the most logical option would be to simply round them. As a rule, the result after that is distorted slightly. So how do you round numbers?
Some important rules for rounding numbers
So, if you want to round a number, is it important to understand the basic principles of rounding? This is an operation to change the decimal fraction, aimed at reducing the number of decimal places. To carry out this action, you need to know a few important rules:
- If the number of the desired digit is between 5-9, rounding up is carried out.
- If the number of the desired digit is between 1-4, rounding down.
For example, we have the number 59. We need to round it up. To do this, you need to take the number 9 and add one to it to get 60. That's the answer to the question of how to round numbers. Now let's consider special cases. Actually, we figured out how to round a number to tens usingthis example. Now it remains only to put this knowledge into practice.
How to round a number to integers
It often happens that there is a need to round, for example, the number 5, 9. This procedure is not difficult. First you need to omit the comma, and when rounding, the already familiar number 60 appears before our eyes. And now we put the comma in place, and we get 6, 0. And since zeros in decimal fractions, as a rule, are omitted, we end up with the number 6.
A similar operation can be performed with more complex numbers. For example, how to round numbers like 5, 49 to integers? It all depends on what goals you set for yourself. In general, according to the rules of mathematics, 5.49 is still not 5.5. Therefore, it cannot be rounded up. But you can round it up to 5, 5, after which rounding up to 6 becomes legal. But this trick does not always work, so you need to be extremely careful.
How to correctly round numbers after the decimal point to tenths?
In principle, an example of the correct rounding of a number to tenths has already been considered above, so now it is important to display only the main principle. In fact, everything happens in approximately the same way. If the digit that is in the second position after the decimal point is within 5-9, then it is generally removed, and the digit in front of it is increased by one. If less than 5, then this figure is removed, and the previous one remains in its place.
For example,when rounding the number 4.59 to 4.6, the number "9" goes away, and one is added to the five. But when rounding 4, 41 units are omitted, and the four remain unchanged.
How do marketers use the inability of the mass consumer to round numbers?
It turns out that most people in the world do not have the habit of evaluating the real cost of a product, which is actively exploited by marketers. Everyone knows stock slogans like "Buy for only 9.99." Yes, we consciously understand that this is already, in fact, ten dollars. Nevertheless, our brain is arranged in such a way that it perceives only the first digit. So the simple operation of bringing the number into a convenient form should become a habit.
Very often, rounding allows a better estimate of intermediate success, expressed in numerical form. For example, a person began to earn $ 550 a month. An optimist will say that this is almost 600, a pessimist - that it is a little more than 500. It seems that there is a difference, but it is more pleasant for the brain to "see" that the object has achieved something more (or vice versa).
There are countless examples where the ability to round is incredibly useful. It is important to be creative and, if possible, not to be loaded with unnecessary information. Then success will be immediate.
