You know that the prefix mili means one thousandth or 1/100.
Numerically speaking, one thousandth is equals to 10 to the power of negative 3.
Solving seconds to milliseconds:
6.7 seconds x 1000 milliseconds / 1 second
Cancelling out the unit seconds. Then multiplying 6.7 to 1000 milliseconds.
The answer is 6,700 milliseconds or 6.7 x 10^3 ms
