Let \( x \) be the number of packages Sam bought. Each package contains 9 beads, so the total number of beads Sam bought can be expressed as \( 9x \).
According to the problem, Sam's mom bought him 63 more beads. So, the total number of beads he has after receiving the extra beads is:
\[ 9x + 63 = 153 \]
Now, we can solve for \( x \). First, subtract 63 from both sides:
\[ 9x = 153 - 63 \] \[ 9x = 90 \]
Next, divide both sides by 9 to find \( x \):
\[ x = \frac{90}{9} \] \[ x = 10 \]
Therefore, Sam bought \( \boxed{10} \) packages.