How to apply a percentage formula across multiple cells/single worksheet

Originally Posted by martindwilson

put 0.85 in a spare cell copy select range of figures paste special multiply

Hi Martin,

Many thanks for this, unfortunately I'm not very IT literate, can you explain further, I can't work out where the formula is....basically I need the full dumbing down treatment with step-by-step guide, I haven't used Excel for over 10yrs...

Thank you,
Claire