Put 7 red pencils and 3 blue pencils in a bag, and let you pick out one at a time, and then put it back in the bag. If you touch 1000 times in this way, how many times will you find red pencils?
把7支红铅笔和3支蓝铅笔放在一个包里，让你每次任意摸出1支，然后放回包里，这样摸1000次，摸出红铅笔的情况大约是多少次．
<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">1_000 * (7/10)</gadget>
<output>700</output>

<result>700</result>