Four Fours/66/Solutions/4

Puzzle: Four Fours: $66$

Using exactly $4$ instances of the number $4$, the task is to write an expression for $66$, using whatever arithmetical operations you consider necessary.

Solution

$66 = \dfrac {4!} {.4} + 4 + \sqrt 4$

Sources

• 1964: L.H. Clarke: Fun with Figures ... (previous) ... (next): Solutions: $(46)$