4 |
7 |
=444×0.25+
4 |
7 |
=111+
1 |
7 |
=111
1 |
7 |
(2)27×3.4+15.4×34-340×81%,
=3.4×(27+154-81),
=3.4×100,
=340;
(3)155×
23 |
156 |
11 |
156 |
=156×
23 |
156 |
23 |
156 |
33 |
156 |
=23+
10 |
156 |
=23
5 |
78 |
(4)
1 |
2008 |
2 |
2008 |
3 |
2008 |
2007 |
2008 |
=
(1+2007)+(2+2006)+…(1003+1005) |
2008 |
1004 |
2008 |
=
2008×1003 |
2008 |
1 |
2 |
=1003+
1 |
2 |
=1003
1 |
2 |