Qingfeng stationery store shipped 10,000 brushes more than fountain pens, and (3/7) brushes were the same as fountain pens (1/2). How many thousands of pens did Qingfeng stationery ship in total?
庆丰文具店运来的毛笔比钢笔多1万支，其中毛笔的(3/7)与钢笔的(1/2)支数相同，庆丰文具店共运来多少万支笔？
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) - (3/7)</gadget>
<output>1/14 = around 0.071429</output>

<gadget id="calculator">(3/7) / (1/14)</gadget>
<output>6</output>

<gadget id="calculator">6 + 6 + 1</gadget>
<output>13</output>

<result>13</result>