\(\left\{210:\left[16+3.\left(6+3.2^2\right)\right]\right\}-3\)
\(=\left\{210:\left[16+3.\left(6+3.4\right)\right]\right\}-3\)
\(=\left\{210:\left[16+3.\left(6+12\right)\right]\right\}-3\)
\(=\left\{210:\left[16+3.18\right]\right\}-3\)
\(=\left\{210:\left[16+54\right]\right\}-3\)
\(=\left\{210:70\right\}-3\)
\(=3-3\)
\(=0\)