Master Wang processes a batch of parts, and has already completed (4/9) of this batch of parts. If he makes 10 more parts, it will just complete half of the total number. How many parts has Master Wang completed?
王师傅加工一批零件，已经完成这批零件的(4/9)，如果再做10个就正好完成了总数的一半，求王师傅已经完成零件多少个？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">4 / 9</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">(1/2) - (4/9)</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">10 / (1/18)</gadget>
<output>180</output>

<gadget id="calculator">180 * (4/9)</gadget>
<output>80</output>

<result>80</result>