Final answer:
A slice of whole-wheat bread contains 97 kilocalories, derived from 1 gram of fat, 18 grams of carbohydrate, and 4 grams of protein.
Step-by-step explanation:
A slice of whole-wheat bread contains 1 gram of fat, 18 grams of carbohydrate, and 4 grams of protein. To determine the number of kilocalories in the slice of bread, we need to multiply the grams of each macronutrient by their respective caloric values. Fat has 9 kilocalories per gram, carbohydrate has 4 kilocalories per gram, and protein also has 4 kilocalories per gram.
Number of kilocalories from fat = 1 gram * 9 kilocalories/gram = 9 kilocalories
Number of kilocalories from carbohydrate = 18 grams * 4 kilocalories/gram = 72 kilocalories
Number of kilocalories from protein = 4 grams * 4 kilocalories/gram = 16 kilocalories
Therefore, the slice of whole-wheat bread contains a total of 9 + 72 + 16 = 97 kilocalories.