Mr. Tran needs 96 tiles to cover his kitchen floor.
He already has 60 tiles.
So he needs 96 - 60 = 36 tiles
Tiles come in packages of 4.
So to purchase 36 tiles, he needs to purchase

Hence Mr Tran needs to purchase 9 boxes of 4 tiles each.
The total number of packages Mr. Tran will need to buy to finish covering his kitchen floor are 9.