Why don't mathematicians round Pi to 3?

Answer 1

Mathematicians occasionally will round Pi to 3 when they are willing to accept a 5% error. Usually, they don't round Pi that much, because the problem requires greater precsion. Of course, Pi must always be rounded to some extent, because it is an irrational number. It is common to round Pi to either 3.14 or 3.141592654. The first number is usually used when do problems by hands, and the latter number is the form stored on most calculators under the Pi button. As an example of why mathematicians might not round Pi to three, observe calculating the Earth's circumference using both Pi and 3. Using Pi The Earth's radius is about 3,959 mi. Therefore, using the formula Circumference = Pi time diameter, the circumference would be 24,875.13 mi. Using three: Using the same formula and radius, the circumference would be 23,754 mi. That is over 1,000 miles shorter. Imagine you were trying to calculate how much fuel you would need to circumvent the globe. If you rounded down to three, you would be out of gas about over 1,000 miles short of your destination.