In a tree planting activity, the sixth grade students planted 120 trees, the fifth grade students planted fewer trees than the sixth grade students (1/6), and the fifth grade students planted more trees than the fourth grade students (1/4). How many trees are planted in fourth grade?
在一次植树活动中，六年级同学植树120棵，五年级同学植树比六年级少(1/6)，五年级同学植树比四年级多(1/4)．四年级植树多少棵？
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 - (1/6)</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 + (1/4)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">(5/6) / (5/4)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">120 * (2/3)</gadget>
<output>80</output>

<result>80</result>