题目内容
脱式计算(能简算的要简算)
(1)
÷[
×(
+
)]
(2)
×
-
÷
(3)1999+999×999
(4)33333×66666.
(1)
| 9 |
| 20 |
| 1 |
| 2 |
| 2 |
| 5 |
| 4 |
| 5 |
(2)
| 20 |
| 13 |
| 17 |
| 9 |
| 8 |
| 9 |
| 13 |
| 20 |
(3)1999+999×999
(4)33333×66666.
(1)
÷[
×(
+
)]
=
÷[
×
],
=
×
,
=
;
(2)
×
-
÷
,
=
×
-
×
,
=
×(
-
),
=
×1,
=
;
(3)1999+999×999,
=1999+(1000-1)×999,
=1999+1000×999-999,
=1999+999000-999,
=1999-999+999000,
=1000000;
(4)33333×66666,
=22222×1.5×66666,
=22222×(1.5×666666)
=22222×99999,
=22222×(100000-1),
=2222200000-22222,
=2222177778.
| 9 |
| 20 |
| 1 |
| 2 |
| 2 |
| 5 |
| 4 |
| 5 |
=
| 9 |
| 20 |
| 1 |
| 2 |
| 6 |
| 5 |
=
| 9 |
| 20 |
| 5 |
| 3 |
=
| 3 |
| 4 |
(2)
| 20 |
| 13 |
| 17 |
| 9 |
| 8 |
| 9 |
| 13 |
| 20 |
=
| 20 |
| 13 |
| 17 |
| 9 |
| 8 |
| 9 |
| 20 |
| 13 |
=
| 20 |
| 13 |
| 17 |
| 9 |
| 8 |
| 9 |
=
| 20 |
| 13 |
=
| 20 |
| 13 |
(3)1999+999×999,
=1999+(1000-1)×999,
=1999+1000×999-999,
=1999+999000-999,
=1999-999+999000,
=1000000;
(4)33333×66666,
=22222×1.5×66666,
=22222×(1.5×666666)
=22222×99999,
=22222×(100000-1),
=2222200000-22222,
=2222177778.
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