Physics-Watt and Calorie problem (please help explain this to me-very lost)

Question

In an average human, basic life processes require energy to be supplied at a steady rate of 100 W.

1. What daily energy intake, in Calories, is required to maintain these basic processes?

Answer 1

Converting Watts = Joules/s to Calories/day (I assume nutritional calories that are actually kcal - often written as Cal vs. cal))

cancel units to get to the units you want and all conversion factors are unitary in that the numerator ant denominator are equal - they change the units without changing the measurement or data.

100J/s * 4.184 cal/Joule * 1kcal/ 1000 cal * 3600 s/hr * 24hr/d = Cal/day

Please consider a tutor. Take care.