In the "June 1st" Children's Painting and Calligraphy Competition, the number of winners in the sixth grade is the number of winners in the fifth grade (6/7), and the number of winners in the fourth grade is the number of winners in the fifth grade (5/7). It is known that there are 84 winners in the sixth grade, how many winners are there in the fourth grade?
庆"六一"儿童书画比赛中，六年级获奖人数是五年级获奖人数的(6/7)，四年级获奖人数是五年级的(5/7)．已知六年级获奖人数有84，四年级获奖人数有多少人？
<gadget id="calculator">6 / 7</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">84 / (6/7)</gadget>
<output>98</output>

<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">98 * (5/7)</gadget>
<output>70</output>

<result>70</result>