解:741-599等于( 142 )
∵已知需求出741-599等于多少
方法一
741 - 599
= 741 - (600 - 1)
= 741 - 600 + 1
= 141 + 1
= 142
方法二
741 - 599
= (700 + 41)- (600 - 1)
= 700 + 41 - 600 + 1
= (700 - 600)+ (41 + 1)
= 100 + 42
= 142
答:741-599等于142
两边同时加1就好了741+1-599+1=742-600=142
741-599
=741-(600-1)
=741-600+1
=141+1
=142
=741-600+1
=141+1
=142