Master Li packs the school uniforms of the fifth and sixth grades of a certain elementary school. If there are a certain number of pieces in each box, it can be filled; if there are more than 20 pieces in each box, only 7/9 of the original box number is needed; If there are at least 20 pieces in each box, then use 2 more boxes. Q How many school uniforms are there for the fifth and sixth grades?
李师傅为某小学的五、六年级的校服进行包装，如果每箱装一定的件数，正好可以装完；如果每箱多装20件，只需原来箱数的(7/9)；如果他每箱少装20件，那么就多用2个箱子．问五、六年级的校服有多少件？
<gadget id="calculator">7 / 9</gadget>
<output>7/9 = around 0.777778</output>

<gadget id="calculator">20 * (7/9)</gadget>
<output>140/9 = around 15.555556</output>

<gadget id="calculator">1 - (7/9)</gadget>
<output>2/9 = around 0.222222</output>

<gadget id="calculator">(140/9) / (2/9)</gadget>
<output>70</output>

<gadget id="calculator">70 * 5</gadget>
<output>350</output>

<result>350</result>