When a number is divided by 9, the quotient is 5 and the remainder is 4. What is the number?
一个数除以9，商是5，余数是4，这个数是多少．
<gadget id="calculator">9 * 5</gadget>
<output>45</output>

<gadget id="calculator">45 + 4</gadget>
<output>49</output>

<result>49</result>