望下2嗰原碼

'''2'''係[[1]]同[[3]]之間嗰[[自然數]]。

集合論中，2 拕定義為{0,1}。
* 係第一隻質數

== 普通計算 ==

{|class="wikitable" style="text-align: center; background: white"
|-
!width="105px"|[[乘法]]
!1
!2
!3
!4
!5
!6
!7
!8
!9
!10
!width="5px"|
!11
!12
!13
!14
!15
!16
!17
!18
!19
!20
!width="5px"|
!21
!22
!23
!24
!25
!width="5px"|
!50
!100
!1000
|-
|<math>2 \times x</math>
|'''2'''
|[[4]]
|[[6]]
|[[8]]
|[[10]]
|[[12]]
|[[14]]
|[[16]]
|[[18]]
|[[20]]
!
|[[22]]
|[[24]]
|[[26]]
|[[28]]
|[[30]]
|[[32]]
|[[34]]
|[[36]]
|[[38]]
|[[40]]
!
|[[42]]
|[[44]]
|[[46]]
|[[48]]
|[[50]]
!
|[[100]]
|[[200]]
|[[2000]]
|}

{|class="wikitable" style="text-align: center; background: white"
|-
!width="105px"|[[除法]]
!1
!2
!3
!4
!5
!6
!7
!8
!9
!10
!width="5px"|
!11
!12
!13
!14
!15
|-
|<math>2 \div x</math>
|'''2'''
|1
|<math>0.\overline{6}</math>
|0.5
|0.4
|<math>0.\overline{3}</math>
|<math>0.\overline{2}8571\overline{4}</math>
|0.25
|<math>0.\overline{2}</math>
|0.2
!
|<math>0.\overline{1}\overline{8}</math>
|<math>0.1\overline{6}</math>
|<math>0.\overline{1}5384\overline{6}</math>
|<math>0.\overline{1}4285\overline{7}</math>
|<math>0.1\overline{3}</math>
|-
|<math>x \div 2</math>
|0.5
|1
|1.5
|'''2'''
|2.5
|3
|3.5
|4
|4.5
|[[5]]
!
|5.5
|6
|6.5
|[[7]]
|7.5
|}

{|class="wikitable" style="text-align: center; background: white"
|-
!width="105px"|[[指數]]
!1
!2
!3
!4
!5
!6
!7
!8
!9
!10
!width="5px"|
!11
!12
!13
|-
|<math>2 ^ x\,</math>
|'''2'''
|4
|8
|16
|32
|[[64]]
|[[128]]
|[[256]]
|[[512]]
|[[1024]]
!
|[[2048]]
|[[4096]]
|[[8192]]
|-
|<math>x ^ 2\,</math>
|1
|4
|[[9]]
|16
|[[25]]
|36
|[[49]]
|64
|[[81]]
|[[100]]
!
|[[121]]
|[[144]]
|[[169]]
|}

== 另寫 ==
* 貳
* 弍
* 二

[[Category:整數]]