$\left ( {1} \right )$$827-347-253$
$=827-(347+253)$
$=827-600$
$=227$
$\left ( {2} \right )$$4200\div 4\div 25$
$=4200\div (4\times 25)$
$=4200\div 100$
$=42$
$\left ( {3} \right )$$65\times 96+4\times 65$
$=(96+4)\times 65$
$=100\times 65$
$=6500$
$\left ( {4} \right )$$164+\left ( {318+36} \right )$
$=\left ( {164+36} \right )+318$
$=200+318$
$=518$