Processing a batch of parts, A alone takes 12 hours to complete, B alone takes 18 hours, two people cooperate, B makes 140 fewer parts than A, how many parts are there in this batch?
加工一批零件，甲单独做要12小时完成，乙独做要18小时，两人合作，乙比甲少做140个，这批零件一共有多少？
<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">1 / 18</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">(1/12) + (1/18)</gadget>
<output>5/36 = around 0.138889</output>

<gadget id="calculator">1 / (5/36)</gadget>
<output>36/5 = around 7.2</output>

<gadget id="calculator">(36/5) * (1/12)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(36/5) * (1/18)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(3/5) - (2/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">140 / (1/5)</gadget>
<output>700</output>

<result>700</result>