Xiao Ming is carrying a schoolbag and weighs 30 kg, and the school bag is 2 kg. What is Xiao Ming's actual weight?
小明背着书包称体重是30千克，书包2千克，小明实际体重是多少千克
<gadget id="calculator">30 - 2</gadget>
<output>28</output>

<result>28</result>