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Last updated on May 26th, 2025

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Square Root of 8

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The square root of 8 is a value “y” such that when “y” is multiplied by itself → y ⤫ y, the result is 8. The number 8 has a unique non-negative square root, known as the principal square root.

Square Root of 8 for Singaporean Students
Professor Greenline from BrightChamps

What Is the Square Root of 8?

The square root of 8 is ±2.82842712475, where 2.82842712475 is the positive solution of the equation x2 = 8. Finding the square root is just the inverse way of squaring a number, and hence, squaring 2.82842712475 will result in 8.

The square root of 8 is written as √8 in radical form, where the ‘√’  sign is called the “radical”  sign. In exponential form, it is written as (8)1/2.

 

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Square Root of 8 By Prime Factorization

The prime factorization of 8 can be found by dividing the 8 by prime numbers and continuing to divide the quotients until they can’t be divided anymore. After factorizing 8, make pairs out of the factors to get the square root. If there exist numbers that cannot be made pairs further, we place those numbers with a “radical” sign along with the acquired pairs.

 

So, Prime factorization of 8 = 2 × 2 × 2 = 2³

 

But here, only a pair of factor 2 can be obtained and a single 2 is remaining

 

So, it can be written as  √8 =  2√2.

 

Square root of 8 = √[2 × 2 × 2] = 2√2, i.e., 2.82842712475

 

Professor Greenline from BrightChamps

Square Root of 8 By Long Division

This is a method, mainly used for obtaining the square root for non-perfect squares. It usually involves the division of the dividend by the divisor, getting a quotient and a remainder too, where the dividend is the number we are finding the square root of.

 

Follow the steps to calculate the square root of 8:

 

 Step 1: Place the number 8, just the same as the image, starting from right to left, and draw a bar above the pair of digits since 8 is a 1-digit number, so simply just draw a bar above 8. 

 

Step 2: Now, find the greatest number whose square is less than or equal to 8. Here, it is 2, because 22=4 < 8

 

Step 3: Now divide 8 by 2 (the number we got from step 2) and we get a remainder. Double the divisor 2, we get 4 and find the largest possible number A, put it in the right of 4, through this, a double-digit is formed. Now multiply this with the same number A. Repeat this process until you reach the remainder of 0.

 

Step 4: The quotient we got is the square root. In this case, it is 2.828….

 

Professor Greenline from BrightChamps

Square Root of 8 By Approximation

Follow the steps below: 

 

Step 1: find the square roots of the perfect squares above and below 8

 

Below : 4 → square root of 4 =2  …. (i)

 

Above : 9 →square root of 9 = 3 …..(ii)

 

Step 2: Dividing 8 with one of 2 or 3 

 

If we choose 3 and divide 8 by 3, we are getting 2.666 …..(iii)

 

Step 3:  find the average of 3 (from step (ii)) and 2.666 (from step (iii))

 

(3+2.666)/2 = 2.8333 

 

Hence, 2.8333 is the approximate square root of 8

Max Pointing Out Common Math Mistakes

Common Mistakes and How to Avoid Them in the Square Root of 8

When we find the square root of 8, we often make some key mistakes, especially when we solve problems related to that. So, let’s see some common mistakes and their solutions.

 

Mistake 1

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Misunderstanding symbol

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Often, when √8 is mistaken as 82, we square 8 and get the result as 64. So, understanding of symbols should be clear.

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Square Root of 8 Examples

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Problem 1

Estimate the value of √8 using an initial guess of 2.5

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By using the formula,


New Guess=(Initial Guess + (Given Number / Initial Guess))/ 2


applying the formula, 


New guess= (2.5 + (8/2.5))/2 


                 = (2.5+ 3.2)/2


                 =5.7/2


                 =2.85


Again, repeating the process,


New guess= (2.85 + (8/2.85))/2 


                 = (2.85+ 2.807)/2


                 =5.657/2


                 =2.825


hence, after a few iterations, the value of √8 is approximately 2.825

 

Answer: 2.825 approx.
 

Explanation

Using the formula for New Guess, we found the approximate value of the square root 8 by repeated iterations, where  New Guess=(Initial Guess + (Given Number / Initial Guess))/ 2
 

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Problem 2

Find the length of a side of a square whose area is 8 cm².

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 Given, the area = 8 cm2


We know that, (side of a square)2 = area of square


 Or,  (side of a square)2 = 8


Or,  (side of a square)= √8


Or, side of a square = ± 2√2.


But, the length of a square is a positive quantity only, so, the length of the side is 2√2 cm.

 

Answer: 2√2 cm

 

Explanation

We know that, (side of a square)2 = area of square. Here, we are given with the area of the square, so, we can easily find out its square root because the square root is the measure of the side of the square.

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Problem 3

Simplify (√8 + √8) ⤫ √8

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 (√8 + √8) ⤫ √8 = (2√2 + 2√2) ⤫ 2√2 = 4√2  ⤫ 2√2 = 8 ⤫ 2 =16 

 

Answer: 16

   

Explanation

We first solved the part inside the brackets, i.e., √8 + √8, which resulted into 4√2, and then multiplying it with √8 which is 2√2, we get 16.

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Problem 4

If x= √8, what is x² -3?

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x= √8

 

⇒ x2 = 8

 

⇒ x2-3 = 8-3

 

⇒ x2-3 = 5

 

Answer: 5

 

Explanation

We did the square of the given value of x and then subtracted 3 from it.

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Max, the Girl Character from BrightChamps

Problem 5

If y=√8, find y²

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Firstly, y=√8= 2.8284,

 

Now, squaring y, we get, y2= (2.8284)2=8, or, y2=8

 

Answer: 8

 

Explanation

Squaring “y” which is the same as squaring the value of √8 resulted as 8.

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FAQs on Square Root 8

1.Can the value of √8 be negative?

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2.Is the square root of 8 a whole number?

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3.Is 8 a perfect square or a non-perfect square?

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4.Is the square root of 8 a rational or irrational number?

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5.What is the principal square root of 8?

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6.How does learning Algebra help students in Singapore make better decisions in daily life?

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7.How can cultural or local activities in Singapore support learning Algebra topics such as Square Root of 8?

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8.How do technology and digital tools in Singapore support learning Algebra and Square Root of 8?

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9.Does learning Algebra support future career opportunities for students in Singapore?

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Professor Greenline from BrightChamps

Important Glossaries for Square Root of 8

  • Exponential form: An algebraic expression that includes an exponent. It is a way of expressing the numbers raised to some power of their factors. It includes continuous multiplication involving base and exponent.

 

  • Factorization: Expressing the given expression as a product of its factors

        

  • Prime Numbers: Numbers that are greater than 1, having only 2 factors as →1 and Itself. 

 

  •   Rational numbers and Irrational numbers: The numbers that can be expressed as p/q, where p and q are integers and q is not equal to 0 are called Rational numbers. Numbers that cannot be expressed as p/q, where p and q are integers and q is not equal to 0 are called Irrational numbers. 

 

  • Perfect and non-perfect square numbers: Perfect square numbers are those numbers whose square roots do not include decimal places.  Non-perfect square numbers are those numbers whose square roots comprise decimal places. 

 

Professor Greenline from BrightChamps

About BrightChamps in Singapore

At BrightChamps, we see algebra as more than just symbols—it opens up a world of opportunities! We’re committed to helping children across Singapore develop essential math skills, focusing today on the Square Root of 8 with a special focus on understanding square roots—in an engaging, lively, and simple way. Whether your child is figuring out how fast a roller coaster speeds at Universal Studios Singapore, keeping track of football match scores, or managing their allowance for the newest gadgets, mastering algebra boosts their confidence in daily life. Our interactive lessons make learning fun and accessible. Because kids in Singapore learn in various ways, we customize our teaching to fit each child’s style. From bustling city streets to scenic gardens, BrightChamps makes math come alive throughout Singapore. Let’s make square roots an exciting part of every child’s math adventure!
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Jaskaran Singh Saluja

About the Author

Jaskaran Singh Saluja is a math wizard with nearly three years of experience as a math teacher. His expertise is in algebra, so he can make algebra classes interesting by turning tricky equations into simple puzzles.

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Max, the Girl Character from BrightChamps

Fun Fact

: He loves to play the quiz with kids through algebra to make kids love it.

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