The students planted trees. The fifth grade planted 145 trees, 56 more than the fourth grade. The number of sixth grade trees was 1.5 times that of the fourth and fifth grades. How many trees were planted in the sixth grade?
同学们植树，五年级植树145棵，比四年级多植56棵，六年级植树棵数是四、五年级和的1.5倍，六年级植树多少棵？
<gadget id="calculator">145 - 56</gadget>
<output>89</output>

<gadget id="calculator">89 + 145</gadget>
<output>234</output>

<gadget id="calculator">234 * 1.5</gadget>
<output>351</output>

<result>351</result>