Q&A for How to Find a Square Root Without a Calculator

Return to Full Article

Search
Add New Question
  • Question
    If I have a building that is 40 x 60 feet, how do you find out if it is square?
    Donagan
    Top Answerer
    There are two ways to do it: (1) If you can measure the inside diagonals (from a corner to its opposite corner), the diagonals of a perfect rectangle are equal to each other; (2) Get a magnetic compass and sight it along two adjacent sides. The two directions should be exactly 90° from each other.
  • Question
    How do I calculate the square root without a calculator?
    Community Answer
    Use a factor tree. For example, 625 = 5 x 125 = 5 x 5 x 25 = 5 x 5 x 5 x 5. Because there are 4 fives, and we are looking for the square root, (5 x 5)(5 x 5) = 625. Therefore the square root of 625 is 25.
  • Question
    What is the smallest four-digit whole number divisible by 9 that has two even and two odd digits?
    Community Answer
    The number 1089 is the answer. The way you work it out is 1008 is a 9 time table number. Then just add on nines starting at this number, and the first 9 times table number you get that has two even digits and odd digits is your answer.
  • Question
    The hypotenuse of a triangle is 1.5 m, and another side is 0.5 m. How do I calculate its perimeter in centimeters?
    Donagan
    Top Answerer
    Use the Pythagorean theorem to find the third side, then add the sides together.
  • Question
    How do I calculate square roots with a fraction?
    Community Answer
    To rationalize a denominator, multiply the fraction by a "clever" form of 1. In other words, you need a fraction whose numerator and denominator are both equal to the square root in the denominator.
  • Question
    What are the steps to find a square?
    Donagan
    Top Answerer
    There's only one step: multiply the number by itself. x² = (x)(x).
  • Question
    How can I find the square root of 24 without getting a decimal?
    Donagan
    Top Answerer
    Since the square root of 24 is not an integer, you'll have to accept a decimal.
  • Question
    How do I do square roots without a calculator?
    Donagan
    Top Answerer
  • Question
    What is the mathematical formula for finding square root?
    Donagan
    Top Answerer
    There is no such formula. See Calculate a Square Root by Hand .
  • Question
    How do I find cubed roots without a calculating device?
    Community Answer
    For cubed roots, the cubed root multiplied by itself 3 times will give you the number. So, mathematically, if the quotient obtained on dividing a number by any number is the square of the second number, that's your cubed root. For example, 216/6=36, which is the square of 6. Thus, 6 is the cube root of 216.
  • Question
    What’s the square root of 44?
    Community Answer
    Assuming you can't (or don't want to) use a calculator, we know that the square of 6 is 36, and the square of 7 is 49. So the square root of 44 will be roughly halfway between 6 and 7. So let's square 6.5: that's 42,25. So the number you're looking for is a little larger than 6.5. The square of 6.6 is 43.56. So we're almost there. The square of 6.65 is 44.22. So let's try squaring 6.64: that's 44.09. If that's not close enough for you, try squaring 6.635: that's 44.02. Now square 6.634: that's 44.01. The square of 6.633 is 43.997. So the square root of 44 is slightly larger than 6.633. (In fact, it's 6.6332.)
  • Question
    How do you find 10 times the square root of 2?
    I_l1ke_gam3s
    Community Answer
    The square root of 2 is 1.414. 10 times that is 14.14.
  • Question
    What is the square root of 1600?
    Community Answer
    40.
  • Question
    Can we find square root by long division?
    Donagan
    Top Answerer
    Not in any practical sense. You could use division in a process of trial-and-error, but it could prove to be quite cumbersome in many cases. (In a case where the number happened to be a perfect square, the trial-and-error process could be relatively quick and easy.
  • Question
    Find the square of 21 without actual multiplication?
    Donagan
    Top Answerer
    If you're not allowed to multiply (or use a calculator), you would have to add up 21 21's by hand.
  • Question
    Isn't there an easier and faster way to do it?
    Donagan
    Top Answerer
    Not that anyone's been able to discover.
  • Question
    n squared equals to 9, what does that mean?
    Donagan
    Top Answerer
    That means that n is the square root of 9, which is 3.
  • Question
    How could I find the square of 208?
    Donagan
    Top Answerer
    Assuming you're not using a calculator, you could square 200 (that's 40,000), and to that add the square of 8 (which is 64). 40,000 + 64 = 40,064.
  • Question
    Is there a formula to work out the square root of a number?
    Donagan
    Top Answerer
    Unfortunately, no. The technique shown above is one way to do it without using a calculator, logarithm tables or a slide rule. There are other techniques, too, that consist of a series of successively closer estimations.
  • Question
    How do I manually find the square of a number that's large?
    Donagan
    Top Answerer
    There's no shortcut, assuming you're not using a log table. Manually multiply the number by itself.
Ask a Question

      Return to Full Article