Last updated on May 26th, 2025
If a number is multiplied by the same number, 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, etc. Here, we will discuss the square root of 40.8.
The square root is the inverse of the square of the number. 40.8 is not a perfect square. The square root of 40.8 is expressed in both radical and exponential form.
In radical form, it is expressed as √40.8, whereas (40.8)^(1/2) in exponential form. √40.8 ≈ 6.385, 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.
The prime factorization method is used for perfect square numbers. However, for non-perfect square numbers, the long-division method and approximation method are often used. Let us learn the following methods:
The product of prime factors is the prime factorization of a number. Now let us look at how 40.8 is broken down into its prime factors. However, since 40.8 is not a whole number, we convert it to a fraction 408/10 and factor each part.
Step 1: Finding the prime factors of 408
Breaking it down, we get 2 x 2 x 2 x 3 x 17: 2^3 x 3^1 x 17^1
Step 2: Now we found out the prime factors of 408. The second step is to make pairs of those prime factors. Since 40.8 is not a perfect square, the digits of the number can’t be grouped in pairs evenly. Therefore, calculating 40.8 using prime factorization is more complex and not straightforward.
The long division method is particularly useful 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: To begin with, we need to group the numbers from right to left. In the case of 40.8, we consider it as 40.80.
Step 2: Now we need to find n whose square is less than or equal to 40. The closest perfect square is 36, so n is 6. The quotient is 6, and the remainder is 4.8 after subtracting 36 from 40.8.
Step 3: Bring down 00 to get 480. Add the old divisor with the same number 6 + 6 to get 12, which will be our new divisor prefix.
Step 4: The new divisor will be 12n. We need to find n such that 12n × n ≤ 480. Let us consider n as 3, now 123 × 3 = 369.
Step 5: Subtract 369 from 480 to get the remainder 111.
Step 6: Since the dividend is less than the divisor, add a decimal point. Bringing down two zeroes gives 11100.
Step 7: The new divisor is 126. We find n as 8 because 1268 × 8 = 10144.
Step 8: Subtracting 10144 from 11100 gives a remainder of 956.
Step 9: The quotient is approximately 6.38. Step 10: Continue these steps until the desired decimal precision is achieved.
Therefore, the square root of √40.8 ≈ 6.385.
The approximation method is another method for finding square roots. It is an easy method to find the square root of a given number. Let us learn how to find the square root of 40.8 using the approximation method.
Step 1: We find the closest perfect squares around √40.8.
The smallest perfect square below 40.8 is 36, and the largest above is 49. Thus, √40.8 falls between 6 and 7.
Step 2: Apply the formula: (Given number - smallest perfect square) / (Greater perfect square - smallest perfect square) (40.8 - 36) / (49 - 36) = 4.8 / 13 ≈ 0.369 Adding this to the lower perfect square root: 6 + 0.369 = 6.369, so the square root of 40.8 is approximately 6.369.
Students make mistakes while finding square roots, like forgetting about the negative square root or skipping steps in the long division method. Let us look at a few of these mistakes in detail.
Can you help Max find the area of a square box if its side length is given as √40.8?
The area of the square is approximately 40.8 square units.
The area of the square = side². The side length is given as √40.8.
Area of the square = side² = √40.8 x √40.8 = 40.8.
Therefore, the area of the square box is approximately 40.8 square units.
A square-shaped garden measuring 40.8 square meters is built; if each of the sides is √40.8, what will be the square meters of half of the garden?
20.4 square meters
We can divide the given area by 2 since the garden is square-shaped.
Dividing 40.8 by 2 gives us 20.4.
So half of the garden measures 20.4 square meters.
Calculate √40.8 x 5.
Approximately 31.925
The first step is to find the square root of 40.8, which is approximately 6.385.
The second step is to multiply 6.385 by 5.
So, 6.385 x 5 ≈ 31.925.
What will be the square root of (25 + 15.8)?
Approximately 6.403
To find the square root, we need to find the sum of (25 + 15.8).
25 + 15.8 = 40.8, and then √40.8 ≈ 6.385.
Therefore, the square root of (25 + 15.8) is approximately 6.385.
Find the perimeter of the rectangle if its length ‘l’ is √40.8 units and the width ‘w’ is 10 units.
The perimeter of the rectangle is approximately 32.77 units.
Perimeter of the rectangle = 2 × (length + width).
Perimeter = 2 × (√40.8 + 10) ≈ 2 × (6.385 + 10) ≈ 2 × 16.385 ≈ 32.77 units.
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.
: He loves to play the quiz with kids through algebra to make kids love it.