When a number is divided by 6, the quotient is 15 and the remainder is 4. What is the number?
一个数除以6，商是15，余数是4，这个数是多少．
<gadget id="calculator">6 * 15</gadget>
<output>90</output>

<gadget id="calculator">90 + 4</gadget>
<output>94</output>

<result>94</result>