Understand Rounding Numbers Simply – Definitions and Examples
Table of Contents
What is Rounding Numbers?
Rounding Numbers is a fundamental concept in mathematics that allows us to simplify and estimate numerical values. It involves adjusting a number to the nearest whole number, making it easier to work with and comprehend. Let’s explore the significance of rounding and how rounding number is applied in various scenarios.
Analogy of Definition
The Concept of Rounding Numbers
Rounding whole numbers involves approximating a given number to the nearest whole number. The process of rounding numbers eliminates the need for dealing with complex decimal values and provides a simplified representation of numerical data. We can round numbers to nearest hundred, nearest ten, and nearest whole number.
Ways to Round Numbers
There are different methods to round numbers, including rounding to the nearest whole number, rounding up, and rounding down. When rounding to the nearest whole number, you identify the whole number that is closest to the given value.
Round-Up and Round-Down
When rouding off a number we either increase or decrease the number being rounded. Rouding up is when we increase the number and rounding down is when we decrease the number. A simple rule to eveluate if we will round down or round up a number is to check the digit to the right of the rouding digit. If the digit to the right is less than 5, we round down the number and if it is equal to or more than 5, we round up the number. We need to be mindful of the place values while rounding numbers.
Round Numbers to the Nearest Ten
We round numbers to the nearest ten by looking at the rightmost digit or the digit in the ones place. For example, if we have to round 547 to the nearest ten, we will get 550, since our rounding digit is 7 which is greater than 5.
Round Numbers to the Nearest Hundred
While rounding numbers to the nearest hundred, we look at the number on the right of the digit in the hundreds place. For example, if we have to round 5637 to the nearest hundred, we will get 5600, since the rounding digit is 3, which is less than 5, so we round down.
Decimals are the numbers in which has both whole number and fractional part which is separated by a decimal point. We consider the decimal place value to round off the numbers. Decimal can be rounded to the nearest tenths, hundreths,thousandth and so on in the similar manner as whole numbers.
Example 1: Rounding 3.7 to the Nearest Whole Number
Step 1: Identify the whole numbers on either side of 3.7
Whole number on the left: 3
Whole number on the right: 4
Step 2: Determine the closest whole number
3.7 is closer to 4 than to 3
So, rounding 3.7 to the nearest whole number gives 4.
Another way to look at it would be, when rouding up decimal to the nearest whole number, we look at the digit in the tenths place which is 7 in this case. As 7 is greater than 5, we round up the number.
Example 2: Rounding 634.82 to the Nearest Tenths
Step 1: As we have to round to the nearest tenth, we look at the digit next to the tenth, which is 2.
Step 2: We will then determine if the digit is greater than or less than 5. In this case, 2 is less than 5.
Step 3: As the digit is less than 5, we will round down and remove all the numbers to the right of the tenths column. Hence the answer will be 634.8
Tips and Tricks
Scenario 1: Rounding 5.6 to the nearest whole number.
Tip: While rounding numbers, a simple rule to keep in mind is that we need to identify the digit which we will round and check the number to its right. In this case, we need to round off 5 as it is the whole number and the number to its right is 6, which is greater than five, so we round up the number. Thus, our answer will be 6.
Scenario 2: Rounding 3251 to the nearest ten
Tip: When rounding numbers to the nearest whole number, consider the whole numbers on either side of the given value and choose the closest whole number.
Calculation:3250 is closer to 3251 than 3260, we will round down to 3250.
Scenari 3: Rounding 2.85 to the nearest tenths.
Tip: Identify the rouding number and check the number next to it.
Calculation: To round number to the nearest tenths, we look at the number to the right which 5, meaning we round up. We add 1 to the number in tenths place and remove all the number to the right of the tenth. Hence, the answer will be 2.9.
Scenario 4: Rounding 7.4 to the nearest whole number.
Tip: When rounding number to the nearest whole number, choose the whole number that is closest to the given value.
Calculation: 7.4 is closer to 7 than to 8, so we choose 8
Scenario 5: Rounding 12.6 to the nearest whole number.
Calculation: 12.6 is closer to 13 than to 12, so we choose 13.
Real life application
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