Before moving ahead to know how to Round off to Nearest 10 let us know some basic things about this. Rounding off a number is a type of estimation in which we convert the actual numbers of different data into adjacent whole numbers.
Actually, We use estimation in our various daily day-to-day life activities. Since mathematics is a subject related to our lives. we also round off the numbers (that we obtained from various measurement activities) up to desired significant figure
Since mathematics is the language of science. it requires changing different quantities to the nearest whole numbers, to analyze and solve various problems. Hence it (how to round a number ) may be very useful for you in your studies.
What is rounding off a Number?
In rounding off we make a number simple and closer to the next number while keeping its value intact.it can be done for whole numbers as well as for decimals up to various places like tens, hundreds or tenths or hundredths, etc…
In rounding off a number while we reduce the number of digits but we preserve the actual value up to given significant figures
Non-zero digits are always considered as significant. The number 23.2 is said to have 3 significant figures. while 1.14157 has six significant digits and 127 has 3 significant figures.
A Significant digit contains all the digits of a number that give us useful information about the digit.
Rounding Rules for Whole Numbers
Although in this post we are talking about rounding to the nearest 10, the rules for rounding off a number is much or less the same only.
As far as rounding off is concerned, the main player is the digit next to the considered significant digit up to which you will have to do the round-off.
Hence the very next para is going to be very important for you
If the next digit is less than 5, then the digit up to which we have to round off doesn’t need any change but if the next digit is 5 or more, then we have to add +1 to the previous digit. In both of these cases, the digit next to the considered significant digit up to which the round-off is to be done will automatically become zero.
Here in this post, we are going to talk about rounding off different numbers in the adjacent 10. for this during rounding off the given number we round off it in multiples of 10 that are close to it.
Rule #1: When the digit at the unit’s place of a given number is a digit between 0 to 4 i.e. smaller than 5, then the digit of the unit’s place is converted to zero while the digit at tens place remains the same.
Rule #2– The 2nd rule of estimation or rounding off tells that if the digit at the unit’s place is the digit from 5 to 9. i.e-if the digit at the unit’s place is greater than or equals to 5 but less than 10. then in this case the digit at unit’s place is changed to 0 while the digit at tens place is increased by +1.
A few questions to understand the concept for Round off to Nearest 10–
To keep it short I am trying to give just 2 examples to make the rule for Round off to Nearest 10 very clear to you …
Q1. Ravi has a total of 64 guavas. Round off the number of guavas to the nearest 10.
Ans: – As mentioned, Ravi has a total of 64 guavas. 64 comes between 60 and 70. If we look at 64 as a number, the digit of its unit’s place is 4 which is less than 5.
In this way, we can say that the number 64 is closer to the number 60. so on the basis of rule 1, its approximate value will be 60.
Q2. Round off 127 to the nearest number of 10
Ans: – The digit at the unit’s place in the number 127 is 7 . Here 7 is greater than 5 so 2nd rule will apply. Hence we convert 7 into 0 and the digit at tens place i.e 2 will be increased by + 1
Hence 130 will be the result of rounding off this number 127 .
127 – > 130
Hope this article Round off to Nearest 10 will be helpful to you to understand the basic concept of rounding off a number. in the future, I will add more numbers of questions to practice.
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