计算下面各题,能简便计算的要简便计算(1)7415-(2415-2.3)(2)4.85×335-3.6+6.15×335(3)0.025×999×2.8×40÷245(4)2001×2001+2001

题目简介

计算下面各题,能简便计算的要简便计算(1)7415-(2415-2.3)(2)4.85×335-3.6+6.15×335(3)0.025×999×2.8×40÷245(4)2001×2001+2001

题目详情

计算下面各题,能简便计算的要简便计算
(1)7
4
15
-(2
4
15
-2.3)
(2)4.85×3
3
5
-3.6+6.15×3
3
5

(3)0.025×999×2.8×40÷2
4
5

(4)
2001×2001+2001
2002×2002-2002

(5)(1-
1
2×2
)(1-
1
3×3
)(1-
1
4×4
)…(1-
1
2001×2001
).
题型:解答题难度:中档来源:不详

答案

(1)7class="stub"4
15
-(2class="stub"4
15
-2.3),
=7class="stub"4
15
-2class="stub"4
15
+2.3,
=5+2.3,
=7.3;

(2)4.85×3class="stub"3
5
-3.6+6.15×3class="stub"3
5

=4.85×3.6-3.6+6.15×3.6,
=(4.85-1+6.15)×3.6,
=10×3.6,
=36;

(3)0.025×999×2.8×40÷2class="stub"4
5

=(0.025×40)×(2.8÷2.8)×999,
=1×1×999,
=999;

(4)class="stub"2001×2001+2001
2002×2002-2002

=
2001×(2001+1)
2002×(2002-1)

=class="stub"2001×2002
2002×2001

=1;

(5)(1-class="stub"1
2×2
)(1-class="stub"1
3×3
)(1-class="stub"1
4×4
)…(1-class="stub"1
2001×2001
),
=(class="stub"1
2
×class="stub"3
2
)×(class="stub"2
3
×class="stub"4
3
)×(class="stub"3
4
×class="stub"5
4
)×…(class="stub"2000
2001
×class="stub"2002
2001
),
class="stub"1
2
×(class="stub"3
2
×class="stub"2
3
)×(class="stub"4
3
×class="stub"3
4
)×…(class="stub"2001
2000
×class="stub"2000
2001
)×class="stub"2002
2001

=class="stub"1
2
×1×1×…×class="stub"2002
2001

=class="stub"1001
2001

更多内容推荐