简便计算
375-98
500-56-44
89+233+511+377+567+123.
解:375-98,
=375-100+2,
=277;
500-56-44,
=500-(56+44),
=500-100,
=400;
89+233+511+377+567+123,
=(89+511)+(233+567)+(377+123),
=600+800+500,
=1900.
分析:375-98,根据减法的运算性质进行简算;
500-56-44,根据减法的运算性质进行简算;
89+233+511+377+567+123,运用加法交换律和结合律进行简算.
点评:此题主要根据加法的运算定律和减法的运算性质进行简算.