
$376-99$
$=376-100+1$
$=276+1$
$=277$
$167+33=200$
$543+102$
$=543+100+2$
$=643+2$
$=645$
$156-28-72$
$=156-\left ( {28+72} \right )$
$=156-100$
$=56$
故答案为:$277$;$200$;$645$;$56$.

$376-99$
$=376-100+1$
$=276+1$
$=277$
$167+33=200$
$543+102$
$=543+100+2$
$=643+2$
$=645$
$156-28-72$
$=156-\left ( {28+72} \right )$
$=156-100$
$=56$
故答案为:$277$;$200$;$645$;$56$.