Question: pounds divided by 2.2 = kg

Answer: 1.) take the pounds and divide by 2

2.) take 10% of the new number

3.) subtract the two numbers

Question: 220lbs to kg

Answer: 220lbs divided by 2 = 110

10% of 110 = 11

110 - 11 = 99kg (so 100kg)

Question: 180 lbs to kg

Answer: 180lbs divided by 2 = 90

10% of 90 = 9

90 - 9 = 81kg (so 80kg)

Question: 160lbs to kg

Answer: 160lbs divided by 2 = 80

10% of 80 = 8

80 - 8 = 72kg

Question: 200lbs to kg

Answer: 200lbs divided by 2 = 100

10% of 100 = 10

100 - 10 = 90kg