Copy the pattern below and continue the pattern for successive powers of $3$.  

$\begin{array}{l} 3^1=3\\ 3^2=9\\ 3^3=\text{___}\\ 3^4=\text{___}\\ \qquad.\\ \qquad .\\ \qquad .\\ 3^9=\text{___} \end{array}$

1. In a sentence or two, describe a pattern formed by the units digits (the “ones”) of the numbers in the pattern. 

   Hint (a):

   Look for repeating numbers.

2. $3^1=3$. List the next three powers of $3$ for which the ones place is a $3$.

   Hint 1(b):

   Look at the pattern in (a) and use it to solve (b).

   Hint 2(b):

   Multiply the previous answer by $3$.

   Answer (b):

   $3^3=27$
   $3^4=81$
   $3^5=243$
   $3^6=729$
   Now find $3^7$, $3^8$, and $3^9$ on your own.