To answer this question, we know that 1km equals 1000m 
and 1 hour is equal to 60 minutes. In the same way 1 minute equals 60 sec onds
 So we have to change the units of elephant speed to km per hour. 
 For this we do the following procedure: 
 1) we multiply 6.9 m / s by the conversion factor from meters to kilometers (1 km / 1000m) 
 

 
 2) The result obtained is multiplied by the conversion factor from seconds to minutes (60s / 1min) 
 

 
 3) The result obtained is multiplied by the conversion factor from minutes to hours (60min / 1hr) 
 

 The answer is 24.84 km / h
 
 You can skip step 2) multiplying 0.0069 km / s by the conversion factor from seconds to hours (3600 s / 1h)