About 0.405 kcal.

According to the unit conversion, the kilogram is the municipal mass unit and the gram is the metric mass unit. The conversion rate between the two is 1 catty = 500 grams. Each 100 grams of potatoes contains about 81 calories. There are 5 100 grams in 500 grams (one pound), so the calories of 500 grams (one pound) of potatoes are: 5 times 81 equals 405 calories. According to the unit conversion, both caloric and kilocalories are units of heat, and the conversion rate between the two is 1000. According to the heat unit conversion formula, 405 calories is equal to 405 divided by 1000, and the calculated result is 0.405 kilocalories.

Therefore, one pound of potatoes is about 0.405 calories