The divisor is 15, the quotient is 21, the remainder is 7, what is the dividend.
除数是15，商是21，余数是7，被除数是多少．
<gadget id="calculator">21 * 15</gadget>
<output>315</output>

<gadget id="calculator">315 + 7</gadget>
<output>322</output>

<result>322</result>