We use pi as 3.14. How can this be right?

Answer 1

It's not right, it's an approximation to 3 significant digits, and for many things, that's close enough.

If you need more sigmificant digits, you can pretty much get as many as you like.

Answer 2

It isn't. It has just been rounded off for simplicity. The actual number goes on forever and has not been found to be reduceable to a fraction. Some use the fraction 22/7 to approximate pi, but this is again just to make the number more manageable for calculations. People can recite pi for thousands of digits and computers have calculated it out to billions of digits, and they have yet to find a pattern. But, for most purposes, the rounded off 3.14 is sufficient.

Answer 3

The degree of accuracy is up to you to choose.

In some cases, pi = 3.14 is good enough. In ancient times, sometimes people use pi = 3 for rough estimate. However, in today's context, one can go to quite a number of decimal places.

Answer 4

Try
http://mathforum.org/dr.math/faq/faq.pi.html

Answer 5

Pi is the ratio of the circumference of a circle to its diameter. The number is 3.14159265358979323846... and goes on forever. This is right because without it the known physics of mathmatics would collapse into a black hole that would swallow our galaxy and crush it into the size of a baseball.

Answer 6

if you want to look at it another way, try this:

4 * lim (1/n) if n is sequential numbers that alternate signs

for example: (1/1 - 1/2 + 1/3 - 1/4 + 1/5...1/n) * 4

the farther you go, the closer to pi

Answer 7

It isn't right. But the real value of pi is irrational, so you can't multiply anything by it. Until about 8th grade, the teachers want you to get practice multiplying.

Answer 8

close enough for your daily needs, and you get to round off on your tests anyway. If you go pro you'll use the pi button on your fancy calculator.

Answer 9

nice of u to think about this stuff logically coz frankly speaking i never gave it a thot but jus accepted it n continued wid my calculations...