To find the numerical equivalent of \( 8^{-3} \), we can use the property of negative integer exponents, which states that:
\[ a^{-n} = \frac{1}{a^n} \]
Applying this property to \( 8^{-3} \):
\[ 8^{-3} = \frac{1}{8^3} \]
Next, we need to calculate \( 8^3 \):
\[ 8^3 = 8 \times 8 \times 8 \]
Calculating step by step:
- \( 8 \times 8 = 64 \)
- \( 64 \times 8 = 512 \)
Thus, \( 8^3 = 512 \).
Now substituting this back into our expression gives:
\[ 8^{-3} = \frac{1}{8^3} = \frac{1}{512} \]
Therefore, the numerical equivalent of \( 8^{-3} \) is:
\[ \frac{1}{512} \]