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Last updated on May 26th, 2025

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Square Root of 40.5

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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 such as vehicle design, finance, etc. Here, we will discuss the square root of 40.5.

Square Root of 40.5 for Vietnamese Students
Professor Greenline from BrightChamps

What is the Square Root of 40.5?

The square root is the inverse of squaring a number. 40.5 is not a perfect square. The square root of 40.5 is expressed in both radical and exponential form.

In radical form, it is expressed as √40.5, whereas in exponential form it is (40.5)^(1/2). √40.5 ≈ 6.36396, 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.

square root of 40.5

Professor Greenline from BrightChamps

Finding the Square Root of 40.5

The prime factorization method is typically used for perfect square numbers. However, for non-perfect square numbers, 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 40.5 by Prime Factorization Method

The product of prime factors is the prime factorization of a number. Since 40.5 is not an integer, it cannot be directly factored into primes. Instead, we can consider the prime factors of the decimal fraction 40.5/1.

 

Step 1: Find the prime factors of 40.5. Breaking it down, we can express 40.5 as 81/2, since 40.5 = 81/2.

 

The prime factorization of 81 is 3 x 3 x 3 x 3.

 

Step 2: Now we have the prime factors of the integer part of 40.5. Since 40.5 is not a perfect square, the digits of the number can’t be grouped in pairs. Therefore, calculating the square root of 40.5 using prime factorization is not straightforward.

Professor Greenline from BrightChamps

Square Root of 40.5 by Long Division Method

The long division method is particularly useful for non-perfect square numbers. Here's how to find the square root using the long division method, step by step:

 

Step 1: Pair the digits from the decimal point towards the left and right. For 40.5, pair '40' and '50'.

 

Step 2: Find a number whose square is less than or equal to 40. Here, 6^2 = 36.

 

Step 3: Subtract 36 from 40, and bring down the next pair (50), making it 450.

 

Step 4: Double the divisor (6), making it 12, and determine the next digit of the quotient.

 

Step 5: Find a digit n such that 12n * n ≤ 450. Here, n = 3, because 123 * 3 = 369.

 

Step 6: Subtract 369 from 450 to get 81.

 

Step 7: Add a decimal point and two zeros to make it 8100. Repeat the process to get more decimal places if needed.

Professor Greenline from BrightChamps

Square Root of 40.5 by Approximation Method

The approximation method is another way to find square roots; it is a simple method for estimating the square root of a given number. Let's learn how to find the square root of 40.5 using this method.

 

Step 1: Identify the closest perfect squares to √40.5. The nearest perfect squares are 36 and 49. √40.5 falls between 6 and 7.

 

Step 2: Apply the formula: (Given number - smallest perfect square) / (Greater perfect square - smallest perfect square).

 

Using the formula (40.5 - 36) / (49 - 36) = 0.346. Adding this value to the lower integer, we get 6 + 0.346 ≈ 6.346, so the approximate square root of 40.5 is 6.346.

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Common Mistakes and How to Avoid Them in the Square Root of 40.5

Students often make mistakes while finding square roots, such as forgetting about the negative square root or skipping steps in the long division method. Let's look at a few common mistakes in detail.

Mistake 1

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Forgetting about the negative square root

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Students should be aware that a number has both positive and negative square roots. However, we typically use the positive square root, as it is the required one. For example, √40.5 ≈ 6.36, but there is also -6.36, which should not be forgotten.

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Square Root of 40.5 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 √40.5?

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The area of the square is approximately 40.5 square units.

Explanation

The area of the square = side². The side length is given as √40.5.

Area = side² = √40.5 × √40.5 = 40.5.

Therefore, the area of the square box is 40.5 square units.

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Max, the Girl Character from BrightChamps

Problem 2

A square-shaped garden measures 40.5 square meters. If each side is √40.5, what is the area of half the garden?

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Approximately 20.25 square meters.

Explanation

Since the garden is square-shaped, dividing the total area by 2 gives the area of half the garden.

40.5 / 2 = 20.25. So, half of the garden measures 20.25 square meters.

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Max, the Girl Character from BrightChamps

Problem 3

Calculate √40.5 × 3.

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Approximately 19.09.

Explanation

First, find the square root of 40.5, which is approximately 6.36.

Then multiply 6.36 by 3. 6.36 × 3 ≈ 19.09.

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Max, the Girl Character from BrightChamps

Problem 4

What will be the square root of (30 + 10.5)?

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Approximately 6.36.

Explanation

First, find the sum of (30 + 10.5). 30 + 10.5 = 40.5, and then find the square root of 40.5, which is approximately 6.36.

Therefore, the square root of (30 + 10.5) is approximately 6.36.

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Max, the Girl Character from BrightChamps

Problem 5

Find the perimeter of a rectangle if its length ‘l’ is √40.5 units and the width ‘w’ is 5 units.

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Approximately 22.72 units.

Explanation

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

Perimeter = 2 × (√40.5 + 5) ≈ 2 × (6.36 + 5) = 2 × 11.36 ≈ 22.72 units.

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FAQ on Square Root of 40.5

1.What is √40.5 in its simplest form?

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2.What are the factors of 40.5?

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3.Calculate the square of 40.5.

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4.Is 40.5 a prime number?

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5.Is 40.5 divisible by any integers?

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Professor Greenline from BrightChamps

Important Glossary for the Square Root of 40.5

  • Square root: A square root is the inverse of squaring a number. For example, 4^2 = 16, and the inverse is √16 = 4.

     
  • Irrational number: An irrational number cannot be expressed as a simple fraction, like √40.5.

     
  • Principal square root: The positive square root of a number, typically used in calculations.

     
  • Approximation: Estimating a number to a certain degree of accuracy, used when precise computation is complex.

     
  • Decimal: A number that consists of a whole number and fractional part, such as 6.36.
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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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