first three digits of your ssn = state of issue (usually state of birth, can’t imagine why his kindergarten ssn number wouldnt be from hawaii)
Until recently, kids didn’t have social security numbers. Now required to claim them as a dependent. Not required in the 60s and 70s.
If the first three numbers indicate state of issuance how can my number be different than my husbands and my Mothers as all were issued in the same state many years apart. Is this a recent thing?