<prompt> A 56-year-old male is burned while sleeping in his home. His right upper and lower extremity and the anterior aspect of the upper chest have extensive second-degree burns.The extent of the burn is calculated to represent what percentage of body surface area?Relative Percentages of Areas Affected by GrowthAreaAge1015Adult A half of head512412312B half of one thigh414412434Relative Percentages of Areas Affected by GrowthAreaAge015A half of head912812612B half of one thigh2343144Table for estimating extent of burns. In adults, a reasonable system for calculating the percentage of body surface burned is the rule of nines--Each arm equals 9, the head equals 9, the anterior and posterior trunk each equals 18, and each leg equals 18; the sum of these percentages is 9910203040  <response>: In calculating burn surface area, the rule of 9s assigns 9 to each upper extremity, 18 to each lower extremity, and 9 to the head and neck. The trunk and abdomen 36 is divided into four equal parts 9 each. Thus, upper trunk anteriorly would be 9. 