The Spring Festival is coming, a supermarket bought 540 small Chinese knots, which is 60 less than the four times of the big Chinese knots purchased, how many big Chinese knots did the supermarket buy? (solution by equation)
春节快到了，某超市购进540只小中国节，比购进的大中国结的4倍少60只，超市购进多少只大中国结？(用方程解)
<gadget id="calculator">60 + 540</gadget>
<output>600</output>

<gadget id="calculator">600 / 4</gadget>
<output>150</output>

<result>150</result>