The digital camera memory card for Matt's camera can store = 900 pictures
Picture's took on Friday= 123'
Picture's took on Saturday= 89
Picture's took on Sunday= 246
(Add the total picture's took on Friday, Saturday and Sunday)
Picture's took on Friday, Saturday and Sunday :- => 123+89+246=> 458
Hence, He took 458 pictures on Friday, Saturday and Sunday.
The digital camera memory card for Matt's camera can store = 900 pictures
The picture's he can take more in his camera:-
=> 900-458
=> 442
Therefore, The picture's he can take more in his camera is 442.