Students donate to "Hope Primary School". The third grade donated 165.7 yuan, the fourth grade donated 28.7 yuan less than the third grade, and the fifth grade donated 45.9 yuan more than the third grade. How much is the total donation for the fourth and fifth grades?
同学们为"希望小学"捐款．三年级捐款165.7元，四年级比三年级少捐28.7元，五年级比三年级多捐45.9元．四、五年级共捐款多少元？
<gadget id="calculator">165.7 - 28.7</gadget>
<output>137</output>

<gadget id="calculator">165.7 + 45.9</gadget>
<output>211.6</output>

<gadget id="calculator">137 + 211.6</gadget>
<output>348.6</output>

<result>348.6</result>