题目内容
计算下列各题.(能简算的要简算)
(1)7.8×
+2.2×20%
(2)0.5×[5
÷﹙
-
﹚]
(3)(198+32×72)-2472÷24
(4)4
×[2.6+
-(0.65+1
)]÷2
.
(1)7.8×
| 1 |
| 5 |
(2)0.5×[5
| 1 |
| 5 |
| 7 |
| 8 |
| 1 |
| 16 |
(3)(198+32×72)-2472÷24
(4)4
| 2 |
| 5 |
| 3 |
| 4 |
| 3 |
| 4 |
| 3 |
| 4 |
(1)7.8×
+2.2×20%,
=7.8×0.2+2.2×0.2,
=(7.8+2.2)×0.2,
=10×0.2,
=2;
(2)0.5×[5
÷﹙
-
﹚],
=0.5×[
÷
],
=0.5×[
×
],
=0.5×
,
=3.2;
(3)(198+32×72)-2472÷24,
=(198+2304)-103,
=[(200-2)+(2300+4)]-103,
=[200+2300+(4-2)]-103,
=2500+2-(100+3),
=2500-100-(3-2),
=2400-1,
=2399;
(4)4
×[2.6+
-(0.65+1
)]÷2
,
=4
×[2.6+
-0.65-1
]÷2
,
=4
×[2.6-0.65-(1
-
)]×
,
=
×[1.95-1]×
,
=
×0.95×
,
=1.52.
| 1 |
| 5 |
=7.8×0.2+2.2×0.2,
=(7.8+2.2)×0.2,
=10×0.2,
=2;
(2)0.5×[5
| 1 |
| 5 |
| 7 |
| 8 |
| 1 |
| 16 |
=0.5×[
| 26 |
| 5 |
| 13 |
| 16 |
=0.5×[
| 26 |
| 5 |
| 16 |
| 13 |
=0.5×
| 32 |
| 5 |
=3.2;
(3)(198+32×72)-2472÷24,
=(198+2304)-103,
=[(200-2)+(2300+4)]-103,
=[200+2300+(4-2)]-103,
=2500+2-(100+3),
=2500-100-(3-2),
=2400-1,
=2399;
(4)4
| 2 |
| 5 |
| 3 |
| 4 |
| 3 |
| 4 |
| 3 |
| 4 |
=4
| 2 |
| 5 |
| 3 |
| 4 |
| 3 |
| 4 |
| 3 |
| 4 |
=4
| 2 |
| 5 |
| 3 |
| 4 |
| 3 |
| 4 |
| 4 |
| 11 |
=
| 22 |
| 5 |
| 4 |
| 11 |
=
| 22 |
| 5 |
| 4 |
| 11 |
=1.52.
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