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Last updated on May 26th, 2025

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Square Root of 243

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If a number is multiplied by itself, the result is a square. The inverse of the square is a square root. The square root is used in fields like vehicle design, finance, and more. Here, we will discuss the square root of 243.

Square Root of 243 for Indonesian Students
Professor Greenline from BrightChamps

What is the Square Root of 243?

The square root is the inverse of the square of the number. 243 is not a perfect square. The square root of 243 is expressed in both radical and exponential form. In the radical form, it is expressed as √243, whereas (243)^(1/2) in the exponential form. √243 ≈ 15.588, which is an irrational number because it cannot be expressed in the form of p/q, where p and q are integers and q ≠ 0.

Professor Greenline from BrightChamps

Finding the Square Root of 243

The prime factorization method is used for perfect square numbers. However, for non-perfect square numbers, the prime factorization method is not applicable, and methods like the long-division method and approximation method are used. Let us now learn the following methods:

 

  • Prime factorization method
  • Long division method
  • Approximation method
Professor Greenline from BrightChamps

Square Root of 243 by Prime Factorization Method

The product of prime factors is the prime factorization of a number. Now let us look at how 243 is broken down into its prime factors:

 

Step 1: Finding the prime factors of 243 Breaking it down, we get 3 x 3 x 3 x 3 x 3: 3^5

 

Step 2: Now we found out the prime factors of 243. The next step is to make pairs of those prime factors. Since 243 is not a perfect square, the digits of the number can’t be grouped into pairs completely. Therefore, calculating 243 using prime factorization directly is not feasible for finding an exact integer square root.

Professor Greenline from BrightChamps

Square Root of 243 by Long Division Method

The long division method is particularly used for non-perfect square numbers. In this method, we should check the closest perfect square number for the given number. Let us now learn how to find the square root using the long division method, step by step:

 

Step 1: Begin by grouping the digits from right to left. In the case of 243, we group it as 43 and 2.

 

Step 2: Identify n whose square is less than or equal to 2. We take n as 1 because 1 x 1 ≤ 2. Now, the quotient is 1, and the remainder is 1 after subtracting 1 from 2.

 

Step 3: Bring down 43, making the new dividend 143. Double the divisor (1) to get 2.

 

Step 4: Find the greatest digit (n) such that 2n x n ≤ 143. We choose n = 5, as 25 x 5 = 125.

 

Step 5: Subtract 125 from 143, leaving a remainder of 18, and update the quotient to 15.

 

Step 6: Since the remainder is less than the divisor, add a decimal point and bring down two zeroes, making the new dividend 1800.

 

Step 7: Find the new divisor, 310, and iterate the process to yield more decimal places, ultimately finding the square root to a desired precision.

 

So the square root of √243 is approximately 15.588.

Professor Greenline from BrightChamps

Square Root of 243 by Approximation Method

The approximation method is another way to find square roots, and it is an easy method to find the square root of a given number. Now let us learn how to find the square root of 243 using the approximation method.

 

Step 1: Identify the closest perfect squares around 243. The nearest perfect squares are 225 (15^2) and 256 (16^2). Thus, √243 falls between 15 and 16.

 

Step 2: Apply the formula: (Given number - smaller perfect square) / (Larger perfect square - smaller perfect square) Using the formula: (243 - 225) ÷ (256 - 225) ≈ 0.58

 

Step 3: Add the decimal value to the smaller integer: 15 + 0.58 = 15.58 Therefore, the square root of 243 is approximately 15.58.

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Common Mistakes and How to Avoid Them in the Square Root of 243

Students often make mistakes while finding square roots, such as forgetting about the negative square root or skipping steps in methods like long division. Here are a few common mistakes in detail.

Mistake 1

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Forgetting about the negative square root

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It is important to remember that a number has both positive and negative square roots. However, we typically consider only the positive square root, as it is the required one in most real-world applications.

For example, √50 = 7.07, but there is also -7.07, which should not be forgotten.

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Square Root of 243 Examples

Ray, the Character from BrightChamps Explaining Math Concepts
Max, the Girl Character from BrightChamps

Problem 1

Can you help Max find the area of a square box if its side length is given as √243?

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The area of the square is 243 square units.

Explanation

The area of a square = side^2.

The side length is given as √243.

Area = (√243 x √243) = 243.

Therefore, the area of the square box is 243 square units.

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Max, the Girl Character from BrightChamps

Problem 2

A square-shaped park measures 243 square feet in area. If each side is √243, what is the area of half of the park?

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121.5 square feet

Explanation

Since the park is square-shaped, to find the area of half of it, divide the total area by 2.

243 / 2 = 121.5

So, half of the park measures 121.5 square feet.

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Max, the Girl Character from BrightChamps

Problem 3

Calculate √243 x 3.

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46.764

Explanation

The first step is to find the square root of 243, which is approximately 15.588.

Then, multiply 15.588 by 3. 15.588 x 3 = 46.764

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Max, the Girl Character from BrightChamps

Problem 4

What will be the square root of (225 + 18)?

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The square root is 15.81

Explanation

To find the square root, first calculate the sum of (225 + 18).

225 + 18 = 243, and then √243 ≈ 15.588.

Therefore, the square root of (225 + 18) is approximately 15.588.

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Max, the Girl Character from BrightChamps

Problem 5

Find the perimeter of a rectangle if its length ‘l’ is √243 units and the width ‘w’ is 10 units.

Ray, the Boy Character from BrightChamps Saying "Let’s Begin"

The perimeter of the rectangle is approximately 51.176 units.

Explanation

Perimeter of the rectangle = 2 × (length + width).

Perimeter = 2 × (√243 + 10)

≈ 2 × (15.588 + 10)

= 2 × 25.588

= 51.176 units.

Max from BrightChamps Praising Clear Math Explanations
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FAQ on Square Root of 243

1.What is √243 in its simplest form?

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2.Mention the factors of 243.

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3.Calculate the square of 243.

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4.Is 243 a prime number?

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5.243 is divisible by?

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

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7.How can cultural or local activities in Indonesia support learning Algebra topics such as Square Root of 243?

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8.How do technology and digital tools in Indonesia support learning Algebra and Square Root of 243?

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

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Professor Greenline from BrightChamps

Important Glossaries for the Square Root of 243

  • Square root: A square root is the inverse operation of squaring a number. For example, if 5^2 = 25, then the square root of 25 is 5.
     
  • Irrational number: An irrational number cannot be expressed as a simple fraction, meaning it cannot be written as p/q, where p and q are integers, and q ≠ 0.
     
  • Principal square root: The principal square root of a number is its non-negative square root, which is usually the one considered in practical applications.
     
  • Prime factorization: Prime factorization is the process of expressing a number as the product of its prime factors. For example, the prime factorization of 243 is 3^5.
     
  • Decimal: A decimal is a number that contains a whole number and a fractional part separated by a decimal point, such as 7.86, 8.65, and 9.42.
Professor Greenline from BrightChamps

About BrightChamps in Indonesia

At BrightChamps, we believe algebra is more than symbols—it’s a doorway to endless possibilities! We aim to help children throughout Indonesia master key math skills, focusing today on the Square Root of 243 with a special emphasis on square roots—in a way that’s fun, lively, and easy to understand. Whether your child is measuring the speed of a roller coaster at Dunia Fantasi, tracking scores in badminton matches, or managing their allowance for the latest gadgets, mastering algebra builds the confidence they need for everyday problems. Our hands-on lessons make learning simple and enjoyable. Because children in Indonesia learn differently, we tailor our approach to fit each learner’s needs. From Jakarta’s bustling streets to Bali’s scenic beaches, BrightChamps brings math to life, making it relevant and exciting across Indonesia. Let’s make square roots a fun part of every child’s math journey!
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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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