To not make it very complicated we can take only three species that will include producer, consumer of the producer, and a predator. We can take the grass, deer, and cougar.
The grass is the producer, and it is the one that has 3,500,000 kilocalories of energy/area. The deer eats the grass, thus gets energy from it, but only 10%, thus the deer will get 350,000 kilcalories of energy/area. The cougar is a predator, and it hunts the deer. When the cougar kills a deer and consumes it, the cougar will get 10% of the energy that the deer got, thus the cougar will get 35,000 kilocalories of energy/area.
