25×44、402+359的简便运算

问题描述:

25×44、402+359的简便运算

25×44
=25×40+25×4
=1000+100
=1100
402+359
=400+1+1+300+59
=700+60+1
=761

25×44
=25X4X11
=100X11
=1100
402+359
=400+2+359
=400+361
=761