SD card was "full" but had no data on

I was trying to take a photo on my Canon camrea however it was saying my SD card was full. I plugged the card  into my cumputer, dragged the 4 photos that were on there on to my desktop, deleted the file “100 CANON”. 

This is what I normally do when downloading and emptying my SD card but I am unsure if its the correct way of doing it as i have never been taught! 

Any help would be appreiciated! 

if you have a Mac and delete files you have to empty the trash before disconnecting the card or the space will not be freed up. Easiest way to fix the issue is to format the card in the camera or computer. Once that is done it should free all the space. next time deleting files from the card make sure and empty the trash before disconnecting the card.  

Thank you!! But how do I format the card??? 

instructions for formatting on a mac linked below. If you want to format on your camera check the camera user manual

https://kb.sandisk.com/app/answers/detail/a_id/203/

How about formatting your  SD Card, I think the problem maybe caused SD card is not property formatted.

  1. At first, insert the SD card in the camera.
  2. Go to “My Computer”.
  3. Now after the SD card is detected, select to the SD card and right click.
  4. After this, select the option “Format”

and here are some ways, hope it can help you: https://www.r-datarecovery.com/sd-card-not-full-but-says-full.html

And maybe you can apply the Bitwar to ensure that you donot suffer from data loss.