The third grade planted 140 trees, and the sixth grade planted three times as many trees as the third grade. Find the total number of trees planted in the two grades.
三年级植树140棵，六年级植树的棵树是三年级的3倍，求两个年级一共植树多少棵．
<gadget id="calculator">3 + 1</gadget>
<output>4</output>

<gadget id="calculator">140 * 4</gadget>
<output>560</output>

<result>560</result>