Xiaodong reads a story book with 278 pages. After reading it for a week, there are only 173 pages left. How many pages does Xiaodong read every day?
小东看一本有278页的故事书，他看了一星期后还剩173页，小东每天看多少页书？
<gadget id="calculator">278 - 173</gadget>
<output>105</output>

<gadget id="calculator">105 / 7</gadget>
<output>15</output>

<result>15</result>