I have a samsung galaxy tab 3 lite,run out of memory have put in 16gb samsung micro sd,still saying no space,what have i done

[maxt]

My sons galaxy tab 3 lite has run out of memory so I have bought a samsung 16gb micro sd card.When I go to download a game it still says no memory.the tablet has recognised the card as it shows on settings.Do i need to back up or something? please help,I am not very technical

 

[Titillating]

http/www.tomsguide.com/forum/id-2327531/moving-apps-card-setting-card-default-download-location.html

That might help.