- #1
soroban
- 194
- 0
If you ever need a 4-by-4 Magic Square,
here's an easy way to construct one.
Draw a 4-by-4 grid
and consider the cells on the two diagonals.
$\quad\begin{array}{|c|c|c|c|} \hline
* &&& *\\ \hline
& * & * & \\ \hline
& * & * & \\ \hline
* &&& * \\
\hline \end{array}$Starting at the upper-left, count 1, 2, 3, ...
and insert the numbers in the diagonal cells.
$\quad\begin{array}{|c|c|c|c|} \hline
\color{red}{1} &&& \color{red}{4} \\ \hline
& \color{red}{6} & \color{red}{7} & \\ \hline
& \color{red}{10} & \color{red}{11} & \\ \hline
\color{red}{13} &&&\color{red}{16} \\ \hline
\end{array}$Now start at the lower-right, count 1, 2, 3, ...
moving up the square, and insert the numbers.
$\quad\begin{array}{|c|c|c|c|} \hline
1 & \color{red}{15} & \color{red}{14} & 4 \\ \hline
\color{red}{12} & 6 & 7 & \color{red}{9} \\ \hline
\color{red}{8} & 10 & 11 & \color{red}{5} \\ \hline
13 & \color{red}{3} & \color{red}{2} & 16 \\ \hline \end{array}$And there is the Magic Square!
Its magic sum is 34.
You will find "34" in various symmetric locations:
the 4 corner cells, the central 2-by-2 cells
the 2-by-2s in each corner, and so on.