It's quite simple: a PowerPoint presentation should have ten slides, last no more than twenty minutes, and contain no font smaller than thirty points.

非常简单：一次PowerPoint陈述，应该只有10页幻灯片，持续时间不超过20分钟，字体不小于30磅。

youdao

Multiplying this parent font by 0.75 results in a smaller font size of 9px.

将这个父字体乘以 0.75 得到一个较小的字体大小 9px。

youdao

The font size of the h1 element is smaller (actually, I hit upon the size I wanted through a little trial and error).

h1 元素的字体大小较小（实际上，我通过一些尝试和错误偶然发现了所需的大小）。

youdao

I'm going to tort-- I'm going to make the font smaller so we can see more.

我们还没看到比较结果,好，你知道我要做什么了么？

麻省理工公开课 - 计算机科学及编程导论课程节选

Some may find the font on the smaller screen to be a bit frustrating, but you can also choose from six font sizes.

ENGADGET: Sony Reader Pocket Edition (PRS-350SC) review

My guess: the smaller font size means Facebook can fit more posts that appear on one screen in the news feed.

FORBES: Facebook: Testing Smaller Font To Make Site 'More Efficient'

The other caveats: Facebook is using the same smaller font size on the new Profile Pages it recently instituted in the News Feed section.

FORBES: New Facebook Profiles: No Downgrade