There are 9 green balls, 210 red balls, 2 less yellow balls than green balls, how many times are there red balls than yellow balls?
绿球有9个，红球有210个，黄球比绿球少2个，红球的个数是黄球的多少倍？
<gadget id="calculator">9 - 2</gadget>
<output>7</output>

<gadget id="calculator">210 / 7</gadget>
<output>30</output>

<result>30</result>