Last updated on May 26th, 2025
If a number is multiplied by itself, the result is a square. The inverse of squaring a number is finding its square root. Square roots are used in various fields such as engineering, finance, and more. Here, we will discuss the square root of 639.
The square root is the inverse operation of squaring a number. 639 is not a perfect square. The square root of 639 can be expressed in both radical and exponential forms. In radical form, it is expressed as √639, whereas in exponential form it is written as (639)^(1/2). The value of √639 is approximately 25.27, which is an irrational number because it cannot be expressed as a simple fraction p/q, where p and q are integers and q ≠ 0.
The prime factorization method is typically used for perfect squares. For non-perfect squares like 639, methods such as the long division method and approximation method are used. Let us now explore these methods:
Prime factorization involves expressing a number as a product of its prime factors. Let's break down 639 into its prime factors:
Step 1: Finding the prime factors of 639 Breaking it down, we get 3 x 3 x 71: 3^2 x 71
Step 2: We found the prime factors of 639. Since 639 is not a perfect square, the digits of the number cannot be grouped into pairs.
Therefore, calculating √639 using prime factorization does not yield an exact result.
The long division method is used for non-perfect squares. Here’s how to find the square root using this method, step by step:
Step 1: Group the digits of 639 from right to left. In this case, we have 39 and 6.
Step 2: Find n such that n^2 is less than or equal to 6. Here, n is 2 because 2^2 = 4, and 4 ≤ 6. The quotient is 2, and the remainder is 6 - 4 = 2.
Step 3: Bring down the next pair, 39, making the new dividend 239. Double the quotient (2), giving us 4, which will be part of our new divisor.
Step 4: Find a digit x such that 4x × x ≤ 239. Let x be 5, as 45 × 5 = 225, and 225 ≤ 239.
Step 5: Subtract 225 from 239 to get a remainder of 14. The quotient is now 25.
Step 6: Since the remainder is less than the new divisor, add a decimal point to the quotient. Bring down a pair of zeros to the dividend, making it 1400.
Step 7: Double the quotient (25) to get 50, then find x such that 50x × x ≤ 1400. Let x be 2, giving 502 × 2 = 1004.
Step 8: Subtract 1004 from 1400 to get 396. The quotient becomes 25.2.
Step 9: Continue this process until you reach the desired decimal precision.
So the square root of √639 is approximately 25.27.
The approximation method is a simpler approach to finding square roots. Let's find the square root of 639 using this method:
Step 1: Identify the nearest perfect squares around 639. Here, 625 (25^2) and 676 (26^2) are the closest.
Step 2: Apply the formula: \( \frac{639 - 625}{676 - 625} = \frac{14}{51} \approx 0.27 \) Using this formula, we find the decimal part of our square root. Add this to the integer part, giving 25 + 0.27 = 25.27.
Therefore, the square root of 639 is approximately 25.27.
Students often make errors when finding square roots, such as forgetting about the negative square root, skipping steps in the long division method, etc. Let's explore some common mistakes and how to avoid them.
Can you help Max find the area of a square box if its side length is given as √639?
The area of the square is approximately 639 square units.
The area of a square = side^2.
The side length is given as √639.
Area of the square = (√639)^2 = 639.
Therefore, the area of the square box is approximately 639 square units.
A square-shaped building measuring 639 square feet is built; if each of the sides is √639, what will be the square feet of half of the building?
319.5 square feet
Since the building is square-shaped, divide the total area by 2 to find half of it.
639 ÷ 2 = 319.5
So half of the building measures 319.5 square feet.
Calculate √639 x 5.
Approximately 126.35
First, find the square root of 639, which is approximately 25.27.
Then, multiply 25.27 by 5.
So, 25.27 × 5 = 126.35.
What will be the square root of (639 + 11)?
The square root is approximately 26.
To find the square root, first compute the sum of 639 + 11.
639 + 11 = 650.
The square root of 650 is approximately 25.5, rounded to 26 for simplicity.
Therefore, the square root of (639 + 11) is approximately ±26.
Find the perimeter of the rectangle if its length ‘l’ is √639 units and the width ‘w’ is 38 units.
The perimeter of the rectangle is approximately 126.54 units.
Perimeter of a rectangle = 2 × (length + width).
Perimeter = 2 × (√639 + 38)
≈ 2 × (25.27 + 38)
= 2 × 63.27
= 126.54 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.
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