2403-399
=2403-(400-1)
=2403-400+1
=2003+1
=2004
解:2403-399等于( 2004 )
∵已知需求出2403-399等于多少
∴2403 - 399
= (2400 + 3)- (400 - 1)
= 2400 + 3 - 400 + 1
= (2400 - 400)+(3 + 1)
= 2000 + 4
= 2004
答:2403-399等于2004
=2400-(400-1)+3
=2400-400+3+1
=2000+4
=2004
2403-399=2400+3-400+1=2000+4=2004