What is Estimation in Maths? Definition With Examples

Introduction

There’s no single way to define estimation. The closest meaning of an estimation is a guess or an assumption about a value that isn’t too far off. What is an estimate in Math? Definition for estimate in math is an approximate value close enough to the correct value. A lot of guesses are made to make math easier and clearer. 

What is Estimation in Maths?

Most of the time, estimation in math is done by rounding off the numbers to their closest whole value to get a quick and simple rough answer. It saves time and effort.

For instance, kids use estimation many times a day without realizing it. They tend to figure out how long they play and how long they have for recess. 

Examples of Estimation

  • Lily counted the number of flowers in the garden by counting the first row and then multiplying it by the number of rows. She estimated that there were 300 flowers in the garden. 
  • Anna made exactly $\$$9.7 from her lemonade stand. When asked by her parents, she estimated that she made about $\$$10 from the stand. 
  • The total population in the world as of April 2022 is around 7.9 billion. This is an estimation. This is not the exact value. 

Non-examples of Estimation

  • There are eight planets in the solar system. 
  • There are 50 states in the United States. 

There is no estimation in both of these examples. They are facts. 

Estimate Symbol Math

Symbol of estimation

We use the first symbol “=” sign when things are exactly the same but if we estimate then we make an approximate guess hence we use the second symbol “ ≈ “ which means ‘approximately equal to’

How to Make an Estimation

The simplest way to estimate is by rounding off numbers to the nearest whole number.  Rounding off helps achieve an approximate answer faster. For example, Laura pays a monthly installment of $\$$3950 for her new house. We can round off this number to $\$$4000 to simplify the calculation. 

The General Rule of Estimation

  • As soon as you pick the number you want to estimate/round, first find the digit at the place you want to round the number to.
  • Next look at the digit right to that place to see which way you will round. 
  • If the digit to the right is four or less (as in 4, 3, 2, 1, 0), your number remains the same. 
  • If the digit to the right is five or higher (as in 5, 6, 7, 8, or nine), your number increases by one. 
  • In the end, all the extra digits that weren’t rounded off, should be removed.

A quick tip to remember this rule is:

Fun way of understanding estimation

Conclusion

Our math specialists are committed to making studying enjoyable for our most ardent readers, the students! 

Teachers investigate all sides of a topic using a compelling and fun learning approach. To know more about estimation concepts and other similarly interesting concepts.

Solved Examples

Example 1. Aaron scored 87.91% in his seventh grade Science finals. Round off his percentage to the nearest whole number. 

Solution: Aaron scored approximately 88% in seventh grade Science finals. This estimation was made after rounding off the number 87.91% to the nearest whole number. Since the number to the right after the decimal is 9 which is greater than 5, the number to the left(7) increases by one digit. 

Example 2. Gina collected 56 coins and Carol collected 86 coins. Choose a better estimate to find the number of coins they own together. 

Solution: Gina collected 56 coins. We can round off 56 to 60 coins and we can round off 86 to 90 coins. After adding 60 and 90, we get 150. The estimated answer is 150. 

Example 3. Sam wants to buy 5 books, each costs $\$$2.95. The bundle of the 5 books together costs $\$$20. Is that correct?

Solution:No, that doesn’t seem correct.

Each book costs approximately $\$$3. Five such books should cost 5 X $\$$3 = $\$$15. 

$\$$20 seems too much.

Practice Problems

What is Estimation in Maths? Definition With Examples

Attend this quiz & Test your knowledge.

1

The seventh grade in a school has 54 students and the eighth grade has 77 students. Which of the following is a better estimation for the total number of students in both grades?

130
140
135
125
CorrectIncorrect
Correct answer is: 130
We can round off 54 to 50 students and 77 to 80 students. Adding 50 and 80 gives us 130. The correct estimation is 130.
2

Which number is obtained when we round off 57.26 to the nearest whole number?

56
57
55
54
CorrectIncorrect
Correct answer is: 57
Rounding off 57.26 to the nearest whole number gives us 57. This is because the number to the right of the decimal is less than 5. When the number to the right of the decimal is less than 5, the number to the left stays the same after rounding off.
3

The moon takes 27.322 days to complete one earth rotation. What is the better estimate?

27 days
28 days
29 days
30 days
CorrectIncorrect
Correct answer is: 27 days
The number to the right of the decimal is less than 5. When the number to the right of the decimal is less than 5, the number to the left stays the same after rounding off.
4

What is the better estimate for the number 368.899 when we round it off to the nearest hundred?

368
369
400
399
CorrectIncorrect
Correct answer is: 400
The number to the right of the hundred is greater than 5. When the number to the right of the hundred is greater than 5, the hundreds place is increased by 1 and is followed by zeros at the tens and ones places.

Frequently Asked Questions

In mathematics, we focus heavily on accuracy. However, in some cases, the guess provides a speedy and almost correct response. As a result, we estimate in math to achieve a rapid and solid response.

Estimation can help you save time and effort on large projects. It also aids in the evaluation of any project’s feasibility. It allows us to get a clearer understanding of the situation.

To get a rough approximation of the total sum, round all the numbers to the same place value, then add them together. To calculate the difference, round all the values to the same place value and then subtract them.

To estimate fractions, round each fraction to the nearest 0, ½ , or 1. 

1/13 can be rounded off to 0 whereas 5/9 can be rounded off to ½.