Help needed

5√32 ?

$$5\sqrt{32} \\
=5\sqrt{16\cdot 2} \\
=5 \underbrace{\sqrt{16}}_{=4} \cdot \sqrt{2} \\
=5\cdot 4 \cdot \sqrt{2} \\
=20 \cdot \sqrt{2} \quad | \quad
\boxed{\ \sqrt{2}= 1.41421356237 \ }\\
= 20 \cdot 1.41421356237\\
=28.2842712475$$