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用简便方法计算下面各题:81723+514-61723+0.75;334×8-334+3×3.75;3.07-(3.07-1.8);934+9934+99934+999934.

题目详情
用简便方法计算下面各题:
8
17
23
+5
1
4
-6
17
23
+0.75;            
3
3
4
×8-3
3
4
+3×3.75;
3.07-(3.07-1.8);
9
3
4
+99
3
4
+999
3
4
+9999
3
4
▼优质解答
答案和解析
(1)8
17
23
+5
1
4
-6
17
23
+0.75
=(8
17
23
-6
17
23
)+(0.75+5
1
4

=2+6
=8;
(2)3
3
4
×8-3
3
4
+3×3.75
=(8-1+3)×3.75
=10×3.75
=37.5;
(3)3.07-(3.07-1.8)
=3.07-3.07+1.8
=0+1.8
=1.8;
(4)9
3
4
+99
3
4
+999
3
4
+9999
3
4

=9+
3
4
+99+
3
4
+999+
3
4
+9999+
3
4

=9+99+999+9999+
3
4
+
3
4
+
3
4
+
3
4

=(10-1+100-+1000-1+10000-1)+(
3
4
×4)
=(11110-4)+3
=11109.