(1)运用加法交换律与结合律简算;
(2)运用加法交换律与结合律以及减法的性质简算;
(3)把79看作80-1,运用乘法分配律简算;
(4)运用乘法结合律简算;
67x78+67
=67x(78+1)
=67x(80-1)
=67x80-67x1
=6530-67
=6463
(1)运用加法交换律与结合律简算;
(2)运用加法交换律与结合律以及减法的性质简算;
(3)把79看作80-1,运用乘法分配律简算;
(4)运用乘法结合律简算;
67x78+67
=67x(78+1)
=67x(80-1)
=67x80-67x1
=6530-67
=6463