# 2

213之間嗰自然數

• 係第一隻質數

## 普通計算

${\displaystyle 2\times x}$  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

${\displaystyle 2\div x}$  2 1 ${\displaystyle 0.{\overline {6}}}$  0.5 0.4 ${\displaystyle 0.{\overline {3}}}$  ${\displaystyle 0.{\overline {2}}8571{\overline {4}}}$  0.25 ${\displaystyle 0.{\overline {2}}}$  0.2 ${\displaystyle 0.{\overline {1}}{\overline {8}}}$  ${\displaystyle 0.1{\overline {6}}}$  ${\displaystyle 0.{\overline {1}}5384{\overline {6}}}$  ${\displaystyle 0.{\overline {1}}4285{\overline {7}}}$  ${\displaystyle 0.1{\overline {3}}}$
${\displaystyle x\div 2}$  0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5

${\displaystyle 2^{x}\,}$  2 4 8 16 32 64 128 256 512 1024 2048 4096 8192
${\displaystyle x^{2}\,}$  1 4 9 16 25 36 49 64 81 100 121 144 169