When 18 divides a number, the quotient is 15 and the remainder is 12. What is the number?
18除一个数，商是15，余数是12，这个数是多少．
<gadget id="calculator">15 * 18</gadget>
<output>270</output>

<gadget id="calculator">270 + 12</gadget>
<output>282</output>

<result>282</result>