Students participate in environmental protection activities. The fifth grade clears and transports (3/7) tons of garbage, which is less than the sixth grade (1/7) tons. How many tons of garbage did the fifth and sixth grades collect?
学生参加环保行动．五年级清运垃圾(3/7)吨，比六年级少清运(1/7)吨．五、六年级共清运垃圾多少吨？
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">(3/7) + (1/7) + (3/7)</gadget>
<output>1</output>

<result>1</result>