Perhaps show us a few of the calculations and we can comment ?

Hi john my bad! everything is correct! best way is to use you calculator and not rely too much on the flight computer 🙂
I made a mistake by confusion lol.

[attachment=2621]bob print.jpg[/attachment]

130 kt - 20 : 110kt. Flight computer shows 134 min. But when you do 245 divided by 110 and then times 60 : 133.6. You get more accurate number. And then 133.6 times fuel flow of 44 divided by 60 to get ( 98 ) . same for final reserve 44 x 30 - dev 60 to get 22.
And same again for alternate of 44x28 - dev 60 to get 20.5 then add 6L. Then add all 98+22+20.5+6 : 146.5..

Is this the correct way of doing it or am I Overthinking stuff 🙂 ?

You appear to be on top of the calculation sequences.

However, don't underrate the nav computer - its precision and accuracy is quite adequate for flying calculations. But you do have to use it with some care to make sure that your settings are as reasonably close as you can manage The electronic device will give you far better precision in the answer but that is different to accuracy.

A lot of pilots confuse the two and see the electronic's umpteen decimals as being the way to go. Not really the case. What you need is an acceptable accuracy. The accuracy in flying calculations doesn't require umpteen decimals precision.

Try to avoid rounding off answers part way through calculations. Far better to run to whatever precision you can manage, either nav computer or electronic,, and then round off to whatever precision might be appropriate at the end of the calculation sequence

Thanks mate 🙂