# 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.

## 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:

## 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

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
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
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
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

368
369
400
399
CorrectIncorrect