Xiao Ming reads an 80-page story book. The ratio of the number of pages he has read to the number of remaining pages is 7:3. How many pages has he read?
小明看一本80页的故事书，已看的页数和剩下页数的比是7：3，他看了多少页．
<gadget id="calculator">7 + 3</gadget>
<output>10</output>

<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">80 * (7/10)</gadget>
<output>56</output>

<result>56</result>