PowerPoint Precise Page Setup

[beanstir]

Hi all,

i am currently designing for an event whereby the screen size is 6481px x 1080px


Using microsoft office for Mac 2011, i have worked out a powerpoint equivalent to this would be 129.62cm x 21.6cm

however after setting powerpoint to this custom size, i return to the page setup and the dimensions have changed to 129.63 x 21.61.

can someone tell me why this is happening? and how i can stop this from happening?





I know it is a question of millimetres, although we are designing the slides in photoshop and placing them into powerpoint as jpegs.

With the screen size being 13' x 78' it is imperative that the slides match perfectly as it will be noticeable on a screen this size when the jpegs 'move'

Thanks,