The experimental school held a campus beautification competition. The fifth grade submitted 180 works, which was 1/8 more than the fourth grade. How many works were submitted by the fourth grade?
实验学校办美化校园作品大赛，五年级上交作品180件，比四年级多(1/8)，四年级上交作品多少件？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 + (1/8)</gadget>
<output>9/8 = around 1.125</output>

<gadget id="calculator">180 / (9/8)</gadget>
<output>160</output>

<result>160</result>