SELECT 
   -- case 1: 1130 - 1100 = 0.5 hour (24 on LHS)
   CASE 
      WHEN (TO_DATE('1130', 'HH24MI') - TO_DATE('1100', 'HH24MI')) * 24 = 0.5 
      THEN 
         'EQUAL TO 0.5 HOUR' 
      ELSE 
         'NOT EQUAL TO 0.5 HOUR' 
   END case_1, 
 
   -- case 2: 1130 - 1100  = 0.5 hour (24 on RHS)
   CASE 
      WHEN (TO_DATE('1130', 'HH24MI') - TO_DATE('1100', 'HH24MI')) = 0.5 / 24 
      THEN 
         'EQUAL TO 0.5 HOUR' 
      ELSE 
         'NOT EQUAL TO 0.5 HOUR' 
   END case_2, 
 
   -- case 3: 1130 - 1030  = 1 hour (24 on LHS)
   CASE 
      WHEN (TO_DATE('1130', 'HH24MI') - TO_DATE('1030', 'HH24MI')) * 24 = 1 
      THEN 
         'EQUAL TO 1 HOUR' 
      ELSE 
         'NOT EQUAL TO 1 HOUR' 
   END case_3, 
 
   -- case 4: 1130 - 1030  = 1 hour (24 on RHS)
   CASE 
      WHEN (TO_DATE('1130', 'HH24MI') - TO_DATE('1030', 'HH24MI')) = 1 / 24 
      THEN 
         'EQUAL TO 1 HOUR' 
      ELSE 
         'NOT EQUAL TO 1 HOUR' 
   END case_4, 
 
   -- case 5: 1100 - 1000  = 1 hour (24 on LHS)
   CASE 
      WHEN (TO_DATE('1100', 'HH24MI') - TO_DATE('1000', 'HH24MI')) * 24 = 1 
      THEN 
         'EQUAL TO 1 HOUR' 
      ELSE 
         'NOT EQUAL TO 1 HOUR' 
   END case_5, 
 
   -- case 6: 1100 - 1000  = 1 hour (24 on RHS)
   CASE 
      WHEN (TO_DATE('1100', 'HH24MI') - TO_DATE('1000', 'HH24MI')) = 1 / 24 
      THEN 
         'EQUAL TO 1 HOUR' 
      ELSE 
         'NOT EQUAL TO 1 HOUR' 
   END case_6 
 
FROM DUAL;