问题 填空题
计算:
(1)
7
×
7
=______;(2)
2
×(-
3
)=______;
(3)
2000
=______;(4)
(-16)×9×(-81)
=______.
答案

(1)

7
×
7
=
7×7
=7;

(2)

2
×(-
3
)=-
2×3
=-
6

(3)

2000
=
400×5
=
400
×
5
=20
5

(4)

(-16)×9×(-81)
=
16×9×81
=
16
×
9
×
81
=4×3×9=108.

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