Why does 八 have an extra thing on top?


The similarity between "to enter (入)" and "number 8 (八)" confuses me. What's
the extra part on top of 八?




Not all fonts have that horizontal thing. Here are examples of the same 八
rendered with various fonts installed on my PC:

[![enter image description
here](https://i.stack.imgur.com/utrmP.png)](https://i.stack.imgur.com/utrmP.png)

Basically, that horizontal bar is something similar to
[serifs](https://en.wikipedia.org/wiki/Serif) in Latin fonts. When you write
kanji by hand, you should not try to reproduce it. When in doubt, find a
[教科書体](https://japanese.stackexchange.com/q/18782/5010) font (blue).

Related:

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  * [How often do single dots stick to the top of kanji?](https://japanese.stackexchange.com/q/33687/5010)
  * [Which kanji writing should i follow when writing on paper, digital or non-digital?](https://japanese.stackexchange.com/q/52573/5010)
  * [Is there a reason why the 濁点【だくてん】（ ﾞ）are placed below the stroke at ぐ and で as opposed to the other hiragana characters?](https://japanese.stackexchange.com/q/69005/5010)

