WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<RESTATED>
<CIK> 0001036874
<NAME> NUVEEN TAX-FREE UNIT TRUST
<SERIES> Series 964
<NAME> PENNSYLVANIA INSURED TRUST
<NUMBER> 228
<MULTIPLIER> 1
<CURRENCY> U.S. DOLLARS
<FISCAL-YEAR-END> AUG-31-2000
<PERIOD-START> SEP-01-1999
<PERIOD-END> AUG-31-2000
<PERIOD-TYPE> YEAR
<EXCHANGE-RATE> 1
<INVESTMENTS-AT-COST> 1,573,534
<INVESTMENTS-AT-VALUE> 1,533,935
<RECEIVABLES> 27,091
<ASSETS-OTHER> 0
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 1,562,037
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 27,464
<TOTAL-LIABILITIES> 27,464
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 0
<SHARES-COMMON-STOCK> 16,159
<SHARES-COMMON-PRIOR> 16,495
<ACCUMULATED-NII-CURRENT> 11,382
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> -1,971
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> -39,599
<NET-ASSETS> 1,534,573
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 84,792
<OTHER-INCOME> 0
<EXPENSES-NET> 3,862
<NET-INVESTMENT-INCOME> 80,930
<REALIZED-GAINS-CURRENT> -1,571
<APPREC-INCREASE-CURRENT> 31,042
<NET-CHANGE-FROM-OPS> 110,401
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 81,390
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 17,500
<NUMBER-OF-SHARES-REDEEMED> 1,341
<SHARES-REINVESTED> 0
<NET-CHANGE-IN-ASSETS> -990
<ACCUMULATED-NII-PRIOR> 11,842
<ACCUMULATED-GAINS-PRIOR> -400
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 0
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 0
<AVERAGE-NET-ASSETS> 0
<PER-SHARE-NAV-BEGIN> 0
<PER-SHARE-NII> 0
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> 0
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 0
<EXPENSE-RATIO> 0
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
