The dividend is 57, 1 more than 8 times the divisor, find the divisor.
被除数是57，比除数的8倍多1，求除数．
<gadget id="calculator">57 - 1</gadget>
<output>56</output>

<gadget id="calculator">56 / 8</gadget>
<output>7</output>

<result>7</result>