When Fangfang multiplied a two-digit number by 9, she mistook 9 for 6. The result is 210 less than the correct answer. What should be the correct answer?
芳芳在计算一个两位数乘9时把9错看成6．结果比正确答案少210．正确答案应该是多少？
<gadget id="calculator">9 - 6</gadget>
<output>3</output>

<gadget id="calculator">210 / 3</gadget>
<output>70</output>

<gadget id="calculator">70 * 9</gadget>
<output>630</output>

<result>630</result>