Know your squares: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169 196, 225, ... (Also know that the square of a thousand is a million.) To estimate the square root of 50, for example, since 50 is just a little bigger than 49, its square root is just a little bigger than 7.
There are ways to squeeze one more decimal point out, but they are usually more trouble than they are worth, since calculators are so common. Just think of the square root of 50 as "seven point something".
Using a calculator, the square root of 22 is found to be 4.69041576. However, you can find an approximation without using a calculator: √ 22 = √ (44/2) = √ ((4*11)/2) = 2√ (11/2) = 2 √ 5.5 If you happen to know the square root of both five and six, than you can estimate the square root of 5.5. Alternatively, you could Find the square root of 11 and divide it by the square root of 2. The first method is probably easier. I would estimate the √ 5.5 at about 2.34, which when multiplied by 2 would equal 4.68, which is pretty close to the calculator answer.
384 square feet - without using a calculator !
13.5 square metres - without using a calculator !
One thing that can be calculated using a Square Footage Calculator is the Length and Width of a Rectangle, Circle, Square or Triangle. This comes in handy for calculating room sizes.
Using a calculator, √503 = ± 22.42766 (5dp)
Using a calculator, the square root of 22 is found to be 4.69041576. However, you can find an approximation without using a calculator: √ 22 = √ (44/2) = √ ((4*11)/2) = 2√ (11/2) = 2 √ 5.5 If you happen to know the square root of both five and six, than you can estimate the square root of 5.5. Alternatively, you could Find the square root of 11 and divide it by the square root of 2. The first method is probably easier. I would estimate the √ 5.5 at about 2.34, which when multiplied by 2 would equal 4.68, which is pretty close to the calculator answer.
384 square feet - without using a calculator !
square root of 125= 25 times 5 under the radical (25 has a square root so you can take that out of the radical)= 5 times the square root of 5 (Thats your final answer with no calculator)
13.5 square metres - without using a calculator !
4800 ft2 - without using a calculator !
try to find what number times the same numbers equals the number that you have.
4690 without using a calculator !
540... without using a calculator !
480... WITHOUT using a calculator !
It's really hard to explain in an answer here. See the link for different ways to do it.
The only way, without a calculator, that I know of is long division.
One thing that can be calculated using a Square Footage Calculator is the Length and Width of a Rectangle, Circle, Square or Triangle. This comes in handy for calculating room sizes.