Missing factor using rule of three?

Pawl (view profile)

on 13 Mar 2019
Latest activity Commented on by Pawl

on 13 Mar 2019

the cyclist (view profile)

Hello,
I try to calculate a distance in meter, given the rad values. I use the follwing formula, which is really easy.
0.004 x (m)
--------- = ----------
If I want to know which x(m) corresponds to 4*pi the formula becomes
(0.004*4*pi)/(2*pi)=2*0.004=0.008
This is a result I would expect, but putting the same formula into matlab or any calculator results in
(0.004*4*pi)/2*pi
ans=
0.078956
Next to a missing magnitude it is not 100% correct as well. I think one reason is limited digits of pi, but why is a magnitude missing?
I am sorry for such a trivia question, but maybe someone could give me a hint. I propably think in a wrong direction.

R2017a

the cyclist (view profile)

on 13 Mar 2019
Edited by the cyclist

the cyclist (view profile)

on 13 Mar 2019

Try
(0.004*4*pi)/(2*pi)
The reason your syntax does not work is that it will divide by 2, and then multiply by pi.
See order of operations for details on how expressions are evaluated.

Pawl

Pawl (view profile)

on 13 Mar 2019
Thank you so much, I really struggeld for some days.