Read-only Numbers file for iPad

Hi All,

I would like to send a read-only Numbers file to iPad users.

I create the Numbers file on iMac but tried several methods to make it read-only.

But once I download the Numbers file into the iPad, I still can edit.

Could someone know how I can make it read-only to iPad users even he/she download the Numbers file to the Ipad

Thanks for your help!

Shiloh