For a batch of parts, the master processed all (4/5) less than 20 parts, and the apprentice processed the remaining 42 parts. How many parts are there in total?
一批零件，师傅加工了全部的(4/5)少20个，徒弟加工了余下的42个，这批零件一共多少个？
<gadget id="calculator">42 - 20</gadget>
<output>22</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 - (4/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">22 / (1/5)</gadget>
<output>110</output>

<result>110</result>