The school checked the body. Zhang Wen's weight was 34.6 kg, Qiang Qiang was 2.8 kg heavier than Zhang Wen, and Liu Li was 6.5 kg lighter than Qiang Qiang. How many kg did Liu Li weigh?
学校检查身体，张文的体重是34.6千克，强强比张文重2.8千克，刘丽比强强轻6.5千克，刘丽的体重是多少千克？
<gadget id="calculator">2.8 - 6.5</gadget>
<output>-3.7</output>

<gadget id="calculator">34.6 + (-3.7)</gadget>
<output>30.9</output>

<result>30.9</result>