Determine approximately how much total energy is lost from a three step food chain if 1000 calories enter at the autotroph level

So remember that each level receives 10% of energy from the level before it. So autographs have the 1000 calories, the primary consumers would only get 10% which is 100 calories meaning 900 calories were lost. The secondary consumer would only get 10% which is 10 calories meaning an additional 90 calories were lost. The Total lost amount is 990 calories