There are 154 boys and 126 girls in the sixth grade. Every two people plant a tree. How many saplings are needed?
六年级有男生154人，女生126人，每两人合种一棵树，共需要多少棵树苗？
<gadget id="calculator">154 + 126</gadget>
<output>280</output>

<gadget id="calculator">280 / 2</gadget>
<output>140</output>

<result>140</result>