The fifth grade students collected tree species, the fourth grade collected 25.6 kg, and the fifth grade collected 1.9 kg less than the fourth grade. How many kilograms of tree species did the fourth and fifth graders collect in total?
五年级同学采集树种，四年级采集了25.6千克，五年级比四年级少采集1.9千克．四、五年级同学一共采集树种多少千克？
<gadget id="calculator">25.6 - 1.9</gadget>
<output>23.7</output>

<gadget id="calculator">23.7 + 25.6</gadget>
<output>49.3</output>

<result>49.3</result>