The study of rounding decimals is important specifically in decimal topics of mathematics. Rounding decimals also covered fraction independently. The main purpose of using rounding number method is just to simplify the number keeping its closes value. Rounding number method is used to short the number basically.This is applicable on the right on the numbers only or after the decimal point also involves a number which can increase or decrease the next digit . These numbers helps make values easier or avoid confusion of numbers. Find more detailed information of rounding numbers below;

Round numbers are nothing but the nearest tenths, hundredths etc integer. These numbers are necessary to calculate when we no need to keep many numbers after decimal point.
To rounding decimal step by step method is as follows;
1) Find the positive value of the number.
2) Drop the digits after the decimal if digits are less then five.
3) If the digits after the decimal are equal or grater than five then add 1 to rounding digit.
There are basically 3 rules of rounding numbers. Rounding numbers rules are as follows;
Rule 1: Verify, if the right side decimals are 1,2,3,4 of the given number then simply slum all digits in the right side.
Rule 2: If the right side decimals are 5,6,7,8,9, then add 1 and delete others digits to get the rounding digit.
Rule 3: If above rule are not applicable Then use Banker's rule. Suppose we have some numbers like 3.315; here 5 is dropping as first digit and other decimals are preceding so this will be 3.325 or 3.32.This is also applicable when there is no digit after 5 or digits are following zeros.
The last rule works approximately partially. Half of the time its rounded up and in another half its rounded down.
There are some basic rules to find the nearest 10 rounding number, The rules are as follows;
Rule 1: First find the given round number and the tenth decimal's place of the number. The tenth decimal place is after one place in right side. Let digit after tenth decimal places is less than five, delete all digits after tenth decimal place.
Rule 2: First find the given round number and the tenth decimal's place of the number. The tenth decimal place is after one place in right side. Let digit after tenth decimal places is equal or grater than five, Add 1 in tenth digit to round the hundredth decimal place.
Example:
Let a number is 15.367721 round the number in hundredth decimal places.
Let a number is 15.367721 round the number in hundredth decimal places.
Solution:
Our ‘cutoff point’ comes after the ‘6’ 15.3  67721
This number is greater than 15.3, but lower than 15.4. Look at which is it closer to?
See the 2nd number from the decimal point, that is the number after that ‘cutoff point’.
If the number is 0,1,2,3, or 4 round DOWN to 15.3
If the number is 5,6,7,8, or 9 round UP to the next number 15.4.
Correct answer is 15.4 to 1 decimal places
There are some basic rules to find the nearest 100 rounding number, The rules are as follows;
Rule 1: First find the given round number and the tenth and hundredth decimal's place of the number. The hundredth decimal place is after two place in right side. Let digit after hundredth decimal places is less than five, delete all digits after tenth decimal place.
Rule 2: First find the given round number and the tenth and hundredth decimal's place of the number. The hundredth decimal place is after two place in right side. Let digit after hundredth decimal places is equal or grater than five, Add 1 in hundredth digit to round the thousand decimal place. Repeat the same for tenth decimal place.
Some of the work problems are given below with solution;
Problem 1:
Let a number is 19.367721; round decimals to the nearest hundredth .
Let a number is 19.367721; round decimals to the nearest hundredth .
Solution:
Given 19.367721
Cut off
19.36  7721
19.36<19.367721<19.37
Here the cutoff point is 3rd number after the decimal point
Verify if, 0,1,2,3, or 4 round DOWN to 19.36
Verify if, 5,6,7,8, or 9 round UP to the next number 19.37
So the answer = 19.37 to 2 decimal places
Problem 2:
Round the number 546 to nearest 10
Round the number 546 to nearest 10
Solution:
The given number is 546
The number is ten places is 4 and the number one place is 6
Since number one place is 6 we make it zero
So the number 546 grounded to nearest 10 becomes 550.