how to add up bore and crank

[Bear45-70]

There is a world of difference between 6miles and 6.00miles. They may look the same to you, but if I told someone that I was lost in the woods...

If I said that I was 6 miles from some point, that would mean that I was within 5.5 miles and 6.5 miles of that point Thats a total of 1 mile error

If I said that I was 6.00 miles from some point, that would mean that I am 5.95 miles and 6.05 miles from that point. Thats a total of 0.1 mile error

Which person would be found first?

You are only as accurate as your innacurate number. This is basic physics. This is undeniable. If you disagree with me, please provide supporting and reliable references.

Where the * did you pull the theory that whole numbers has a variation of + or - .5 from is beyond me, except I figure everyone knows where. There is NO + or - standard for a whole number or for any other number with decimal point or not. Of course I have never been lost in the woods.

[Majourlittle]

It comes from rounding errors and drafting. If someone says that they are 6ft tall, and measured themselves with a ruler that has only markings for ft, then it is generally assumed that they are somewhere between 5.50000000000000000 and 6.4999999999999999999999999999 ft tall... since the only accurate unit is the ft ruler, then by signifigant digits you can only show precision to the greatest signifigant digits.

The same logic is used in drafting drawings. You can't make a 3/8" hole in a metal plate. This implies that you are drilling a hole that is 0.375000000000000000 in diameter. You can choose to make a hole that is
0.4 +- 0.05
or
0.38+- 0.005

(this isn't exactly how it would be done, but it demonstrates the point)

[devenex]

As a result of rounding rules and significant figures 6 miles can be anywhere from 5.50 to 6.49 miles. This is where precision comes into play.

As an example lets think about a ruler for a second. You could assume it accurately measures any distance between 0 inches and 12 inches, but just to be safe lets say we use some approved standard to verify that the ruler is in fact exactly one foot in length (i.e. verifying its accuracy), and that this standard show it to be 1.000 ft in length. Unfortunately the notches on this ruler only display down to the eighth of an inch, so even though we have a very accurate ruler we only have precision to 1/8th of an inch. So if something is between say 1 1/2 inches and 1 5/8 inches some estimation must be done in approximating where it lands between those values on the ruler.

Now lets take another instrument, say a caliper. This caliper can read down to the 1/1000th of an inch, so it is more precise than our ruler. Does this mean its more accurate than the ruler? Not necessarily, and the best way to find out would be to verify against the same standard used to test the ruler. If the caliper measures the standard as being slightly less than a foot (say 0.9472 ft), then it is in fact less accurate than the ruler (again assuming the ruler was 1.00 ft) despite having higher precision.

You might be familiar with the term "calibration", and this has to do with keeping an instrument accurate as you could use the standard to calibrate the caliper to read accurately.

[Majourlittle]

I think that we are on different pages, and that we are all right on whatever path we all have taken.

I think that it is mute to continue any further with this. No matter how many digits of pi anyone uses, your displacement calcuated will only be the calcuated displacement accurate to the accurace of your ruler. Im with bear on this and his use of digits. Any more than that, the calculated displacement becomes succeptable to rounding error calcuations.

[maddog]

its simple on a 2 stroke, bore x stroke must be matched foer ultimate performance= no math needed....