When a number is divided by the largest single digit, the quotient is 30 and the remainder is 7. What is the number?
一个数除以最大的一位数，商是30，余数是7，这个数是多少．
<gadget id="calculator">30 * 9</gadget>
<output>270</output>

<gadget id="calculator">270 + 7</gadget>
<output>277</output>

<result>277</result>