The two classes of the fifth grade collected tree species, class 51 collected 14.4 kg, and class 52 collected 2.6 kg more than class 51. How many kilograms of tree species did they collect in total?
五年级的两个班采集树种，五1班采集了14.4千克，五2班比五1班多采2.6千克．他们一共采集树种多少千克？
<gadget id="calculator">14.4 + 2.6</gadget>
<output>17</output>

<gadget id="calculator">17 + 14.4</gadget>
<output>31.4</output>

<result>31.4</result>