One

$$1_{R}$$

The unit element (multiplicative identity) of the ring $R$.

$$1_{\mathbb{Z}} = 1_{\mathbb{Q}} = 1_{\mathbb{C}} = 1$$

All numbers belong to the same 'type'.

$$1_{\operatorname{M}_{2 \times 2} \left(\mathbb{Z}\right)} = \begin{pmatrix} 1 & 0 \\ 0 & 1 \end{pmatrix}$$

A ring with different unit element than the number 1.

Last updated: 2020-03-06 00:22:16