1 kg = 2.2 lb
to set up your proportion
- put your given over one
90lb / 1
then multiply that by you conversion factor which is 1 kg = 2.2 lb
90lb/1 x 1kg/2.2lb
since you have lb on both the top and bottom that unit would cancel out leaving you with kg
if you multiply straight across you get 90 x 1 = 90 and 1 x 2.2 = 2.2
now you just divide the top number by the bottom number 90 ÷ 2.2 = 40.91 kg
