#### Answer

The one similarity between the zero vector and the number $0$ is that they have the same magnitude and that is equal to zero.

#### Work Step by Step

Since, the $\vec{0}$ is written as,
$\vec{0}=\vec{0}\text{i}+\vec{0}\text{j}$
The magnitude of the vector $\vec{v}=a\text{i + }b\text{j}$ is,
$\left| {\vec{v}} \right|=\sqrt{{{a}^{2}}+{{b}^{2}}}$
So, the magnitude of the vector $\vec{0}$ is,
$\begin{align}
& \left| {\vec{0}} \right|=\sqrt{{{0}^{2}}+{{0}^{2}}} \\
& =0
\end{align}$
The magnitude of a scalar quantity is equal to the mode of itself. Since the number $0$ is a scalar quantity, so, the magnitude of $0$ is $0$.
So, the zero vector and number $0$ have the same magnitude and that magnitude is equal to zero.