题目内容
计算下面各题,能用简便方法计算的要用简便方法计算.
|
(873×477-198)÷(476×874+199) | ||||||||||
199.9×19.98-199.8×19.97 |
|
(1)
×[
÷(
+
)],
=
×[
÷
],
=
×
,
=
;
(2)(873×477-198)÷(476×874+199),
=[873×(476+1)-198]÷[476×(873+1)+199],
=[873×476+873-198]÷[476×873+476+199],
=[873×476+675]÷[476×873+675],
=1;
(3)199.9×19.98-199.8×19.97,
=199.9×19.98-19.98×199.7,
=(199.9-199.7)×19.98,
=0.2×19.98,
=3.996;
(4)
×
+16×
+
×
,
=
×
+16×
+
×
,
=(
+
+16)×
,
=(4+16)×
,
=20×
,
=4.
8 |
9 |
3 |
7 |
2 |
3 |
1 |
7 |
=
8 |
9 |
3 |
7 |
17 |
21 |
=
8 |
9 |
9 |
17 |
=
8 |
17 |
(2)(873×477-198)÷(476×874+199),
=[873×(476+1)-198]÷[476×(873+1)+199],
=[873×476+873-198]÷[476×873+476+199],
=[873×476+675]÷[476×873+675],
=1;
(3)199.9×19.98-199.8×19.97,
=199.9×19.98-19.98×199.7,
=(199.9-199.7)×19.98,
=0.2×19.98,
=3.996;
(4)
4 |
5 |
12 |
13 |
1 |
5 |
1 |
5 |
4 |
13 |
=
1 |
5 |
48 |
13 |
1 |
5 |
1 |
5 |
4 |
13 |
=(
48 |
13 |
4 |
13 |
1 |
5 |
=(4+16)×
1 |
5 |
=20×
1 |
5 |
=4.
练习册系列答案
相关题目