Example 1:
$$ \textup{Express } 18 \textup{ in prime factors.}$$
Solution:
$$
\begin{array}{|l}
\llap{2~~~~} 18 \\ \hline
\llap{3~~~~} 9 \\ \hline
\llap{3~~~~} 3 \\ \hline
1
\end{array}
$$
$$ 18=2×3×3$$
$$ 18=2×3^2$$
Example 2:
$$ \textup{Express } 20 \textup{ in prime factors.}$$
Solution:
$$
\begin{array}{|l}
\llap{2~~~~} 20 \\ \hline
\llap{2~~~~} 10 \\ \hline
\llap{5~~~~} 5 \\ \hline
1
\end{array}
$$
$$ 18=2×2×5$$
$$ 18=2^2×5$$
Example 1:
$$ \textup{Express } 54 \textup{ in prime factors.}$$
Solution:
$$
\begin{array}{|l}
\llap{2~~~~} 54\\ \hline
\llap{3~~~~} 27 \\ \hline
\llap{3~~~~} 9 \\ \hline
\llap{3~~~~} 3 \\ \hline
1
\end{array}
$$
$$ 300=2×3×3×3$$
$$ 300=2×3^2$$
Example 2:
$$ \textup{Express } 100 \textup{ in prime factors.}$$
Solution:
$$
\begin{array}{|l}
\llap{2~~~~} 100 \\ \hline
\llap{2~~~~} 50 \\ \hline
\llap{5~~~~} 25 \\ \hline
\llap{5~~~~} 5 \\ \hline
1
\end{array}
$$
$$ 300=2×2×5×5$$
$$ 300=2^2×5^2$$
Example 1:
$$ \textup{Express } 700 \textup{ in prime factors.}$$
Solution:
$$
\begin{array}{|l}
\llap{2~~~~} 700\\ \hline
\llap{2~~~~} 350 \\ \hline
\llap{5~~~~} 175 \\ \hline
\llap{5~~~~} 35 \\ \hline
\llap{7~~~~} 7 \\ \hline
1
\end{array}
$$
$$ 700=2×2×5×5×7$$
$$ 700=2^2×5^2×7$$
Example 2:
$$ \textup{Express } 882 \textup{ in prime factors.}$$
Solution:
$$
\begin{array}{|l}
\llap{2~~~~} 882 \\ \hline
\llap{3~~~~} 441 \\ \hline
\llap{3~~~~} 147 \\ \hline
\llap{7~~~~} 49 \\ \hline
\llap{7~~~~} 7 \\ \hline
1
\end{array}
$$
$$ 300=2×3×3×7×7$$
$$ 300=2×3^2×7^2$$