问题 解答题
脱式计算(能简算的要简算).
①2.5×1.25×32
5
11
×
2
7
+
6
7
×
2
11
2006
2007
×2008
答案

①2.5×1.25×32,

=2.5×1.25×4×8,

=(2.5×4)×(1.25×8),

=10×10,

=100;

5
11
×
2
7
+
6
7
×
2
11

=

5
11
×
2
7
+
2
7
×
6
11

=(

5
11
+
6
11
)×
2
7

=1×

2
7

=

2
7

2006
2007
×2008,

=

2006
2007
×(2007+1),

=

2006
2007
×2007+
2006
2007
×1,

=2006+

2006
2007

=2006

2006
2007

多项选择题
单项选择题 A1/A2型题