用简便方法计算 789-296= 375+298= 25×32×125= 800÷32= 190÷2÷5= 152+261+48+139.

问题描述:

用简便方法计算
789-296=
375+298=
25×32×125= 800÷32=
190÷2÷5= 152+261+48+139.

789-296
=789-300+4
=493;
375+298
=375+300-2
=673;
25×32×125
=(25×4)×(8×125)
=100×1000
=100000;
800÷32
=800÷8÷4
=25;
190÷2÷5
=190÷(2×5)
=19;
152+261+48+139
=(152+48)+(261+139)
=200+400
=600.