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)