(1)(
| 1 |
| 5 |
| 2 |
| 7 |
(2)999
| 8 |
| 9 |
| 8 |
| 9 |
| 8 |
| 9 |
| 1 |
| 3 |
(3)444
| 4 |
| 5 |
(4)231÷231
| 231 |
| 232 |
| 1 |
| 5 |
| 2 |
| 7 |
=
| 1 |
| 5 |
| 2 |
| 7 |
=7+10,
=17;
(2)999
| 8 |
| 9 |
| 8 |
| 9 |
| 8 |
| 9 |
| 1 |
| 3 |
=(1000-
| 1 |
| 9 |
| 1 |
| 9 |
| 1 |
| 9 |
| 1 |
| 3 |
=(1000+100+10)-
| 1 |
| 9 |
| 1 |
| 3 |
=1110-(
| 1 |
| 3 |
| 1 |
| 3 |
=1110;
(3)444
| 4 |
| 5 |
=(444+
| 4 |
| 5 |
| 5 |
| 4 |
=444×
| 5 |
| 4 |
| 4 |
| 5 |
| 5 |
| 4 |
=555+1,
=556;
(4)231÷231
| 231 |
| 232 |
=231÷
| 232×231+231 |
| 232 |
=231×
| 232 |
| (232+1)×231 |
=
| 232 |
| 233 |