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Last updated on May 26th, 2025

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Square Root of 1.8

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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 1.8.

Square Root of 1.8 for Vietnamese Students
Professor Greenline from BrightChamps

What is the Square Root of 1.8?

The square root is the inverse of squaring a number. 1.8 is not a perfect square. The square root of 1.8 is expressed in both radical and exponential form. In radical form, it is expressed as √1.8, whereas in exponential form it is expressed as (1.8)^(1/2). √1.8 ≈ 1.34164, 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 1.8

The prime factorization method is used for perfect square numbers. However, for non-perfect square numbers like 1.8, methods such as the long-division method and approximation method are used. Let us now learn the following methods:

 

  • Long division method
  • Approximation method
Professor Greenline from BrightChamps

Square Root of 1.8 by Long Division Method

The long division method is particularly used for non-perfect square numbers. Let us now learn how to find the square root using the long division method, step by step:

 

Step 1: Start with grouping the digits of 1.8. Since it has only one digit before the decimal, we treat it as 1.8.

 

Step 2: Now, find the largest number whose square is less than or equal to 1. The number is 1, as 1 × 1 = 1. Now, the quotient is 1, and after subtracting, the remainder is 0.

 

Step 3: Bring down 80 (since we add two zeros to the remainder after the decimal point). The new dividend is 80.

 

Step 4: Double the quotient and write it as the new divisor. So, 2 × 1 = 2.

 

Step 5: Find a digit n such that 2n × n is less than or equal to 80. Here, n = 3, since 23 × 3 = 69.

 

Step 6: Subtract 69 from 80. The remainder is 11.

 

Step 7: Bring down two zeros to make it 1100.

 

Step 8: The new divisor becomes 26. Find n such that 26n × n ≤ 1100. Here, n = 4, as 264 × 4 = 1056.

 

Step 9: Subtract 1056 from 1100. The remainder is 44. Step 10: Continue this process to get more decimal places.

 

The square root of 1.8 is approximately 1.34.

Professor Greenline from BrightChamps

Square Root of 1.8 by Approximation Method

The approximation method is another technique for finding square roots. It is an easy method to estimate the square root of a given number. Let us learn how to find the square root of 1.8 using the approximation method.

 

Step 1: Find two perfect squares between which 1.8 falls. The closest perfect squares are 1 (1^2) and 4 (2^2). Therefore, √1.8 falls between 1 and 2.

 

 

Step 2: Apply the interpolation formula: (Given number - smaller perfect square) / (larger perfect square - smaller perfect square). For 1.8, the calculation is (1.8 - 1) / (4 - 1) = 0.8 / 3 ≈ 0.2667.

 

Step 3: Add this value to the smaller root: 1 + 0.2667 ≈ 1.267. Thus, the square root of 1.8 is approximately 1.34, when calculated more precisely.

Max Pointing Out Common Math Mistakes

Common Mistakes and How to Avoid Them in the Square Root of 1.8

Students often make mistakes while finding the square root, such as forgetting about the negative square root or misapplying methods like the long division method. Let us look at 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, in many practical applications, only the positive square root is considered.

For example, √4 = 2, but there is also -2 which should not be neglected.

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Square Root of 1.8 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 √1.8?

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The area of the square is approximately 1.8 square units.

Explanation

The area of a square = side^2.

The side length is given as √1.8.

Area = (√1.8)^2 = 1.8.

Therefore, the area of the square box is approximately 1.8 square units.

Max from BrightChamps Praising Clear Math Explanations
Max, the Girl Character from BrightChamps

Problem 2

A square-shaped garden measuring 1.8 square meters is planned; if each of the sides is √1.8, what will be the square meters of half of the garden?

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

0.9 square meters.

Explanation

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

Dividing 1.8 by 2 gives 0.9.

So, half of the garden measures 0.9 square meters.

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Max, the Girl Character from BrightChamps

Problem 3

Calculate √1.8 x 3.

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Approximately 4.025.

Explanation

First, find the square root of 1.8, which is approximately 1.34164.

Then, multiply 1.34164 by 3.

1.34164 × 3 ≈ 4.025.

Max from BrightChamps Praising Clear Math Explanations
Max, the Girl Character from BrightChamps

Problem 4

What will be the square root of (1 + 0.8)?

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

The square root is 1.34.

Explanation

To find the square root, first find the sum of (1 + 0.8).

1 + 0.8 = 1.8.

The square root of 1.8 is approximately 1.34.

Max from BrightChamps Praising Clear Math Explanations
Max, the Girl Character from BrightChamps

Problem 5

Find the perimeter of the rectangle if its length ‘l’ is √1.8 units and the width ‘w’ is 3 units.

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

The perimeter of the rectangle is approximately 8.68328 units.

Explanation

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

Perimeter = 2 × (√1.8 + 3)

= 2 × (1.34164 + 3)

= 2 × 4.34164

= 8.68328 units.

Max from BrightChamps Praising Clear Math Explanations
Ray Thinking Deeply About Math Problems

FAQ on Square Root of 1.8

1.What is √1.8 in its simplest form?

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2.Mention the factors of 1.8.

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3.Calculate the square of 1.8.

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4.Is 1.8 a prime number?

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5.1.8 is divisible by?

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

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7.How can cultural or local activities in Vietnam support learning Algebra topics such as Square Root of 1.8?

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8.How do technology and digital tools in Vietnam support learning Algebra and Square Root of 1.8?

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

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Professor Greenline from BrightChamps

Important Glossaries for the Square Root of 1.8

  • Square root: The square root is the inverse of squaring a number. For example, if 4^2 = 16, then √16 = 4.
     
  • Irrational number: An irrational number is one that cannot be expressed as a simple fraction or ratio of two integers. For example, √2 is irrational.
     
  • Approximation: Finding a value that is close to but not exactly equal to the true value. For example, √2 ≈ 1.414.
     
  • Long division method: A process used to find the quotient of two numbers, often used to calculate square roots of non-perfect squares.
     
  • Decimal: A number that has a fractional part separated by a decimal point, such as 1.34 or 3.56.
Professor Greenline from BrightChamps

About BrightChamps in Vietnam

At BrightChamps, we know algebra is more than symbols—it’s a path to countless opportunities! Our goal is to help children across Vietnam grasp essential math skills, with today’s focus on the Square Root of 1.8 and a special look at square roots—in an engaging, enjoyable, and easy-to-learn way. Whether your child is figuring out how fast a roller coaster moves at Suoi Tien Theme Park, keeping track of local football scores, or budgeting their allowance for new gadgets, mastering algebra gives them the confidence to handle daily challenges. Our interactive lessons make learning easy and fun. Since children in Vietnam learn in different ways, we adapt to each learner’s style. From Ho Chi Minh City’s vibrant streets to the beautiful Ha Long Bay, BrightChamps makes math come alive throughout Vietnam. 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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