In the first 15 days before Zhang Zhi planned to write 984 large characters, he wrote an average of 40 characters per day. Later, I wrote 48 every day. How many days will it take to finish writing?
张志计划写984个大字前15天平均每天写40个．后来每天写48个，还需要多少天才能写完？
<gadget id="calculator">40 * 15</gadget>
<output>600</output>

<gadget id="calculator">984 - 600</gadget>
<output>384</output>

<gadget id="calculator">384 / 48</gadget>
<output>8</output>

<result>8</result>