How many children can you account for on previous censuses in relation to the number shown as born alive on the 1911 entry?
Use GRO online to find births with the same mothers maiden name - then link that info to the living children & any unaccounted for should be deceased.
If a baby only lived for a minute after birth - it’s birth should be registered but depending on what years are involved - you have to bear in mind that failure to register a birth only became a fineable offence in 1874