How many copper atoms are in a pure copper statue with a mass of 176 kg?

$\frac{176 \times {10}^{3} \cdot g}{63.55 \cdot g \cdot m o {l}^{-} 1} \times {N}_{A}$, where ${N}_{A} = \text{Avogadro's number}$.
${N}_{A} = \text{Avogadro's number} , 6.022 \times {10}^{23} \cdot m o {l}^{-} 1$
We know that ${N}_{A}$ copper atoms have a mass of $63.55$ $g$. How do we know this?