1 |
4 |
=(1.8+2.2)×25%,
=4×25%,
=1;
(2)99×61.25+61.25,
=(99+1)×61.25,
=100×61.25,
=6125;
(3)
9 |
20 |
1 |
2 |
2 |
5 |
4 |
5 |
=
9 |
20 |
1 |
2 |
6 |
5 |
=
9 |
20 |
3 |
5 |
=
3 |
4 |
(4)45+99×99+54,
=(45+54)+99×99,
=99+99×99,
=(99+1)×99,
=100×99,
=9900.
1 |
4 |
9 |
20 |
1 |
2 |
2 |
5 |
4 |
5 |
1 |
4 |
9 |
20 |
1 |
2 |
2 |
5 |
4 |
5 |
9 |
20 |
1 |
2 |
6 |
5 |
9 |
20 |
3 |
5 |
3 |
4 |