问题 解答题
口算.
220+60=
780-290=990+990=55÷8=50×5=
73÷9=600×8=37÷4=6×23=41×6=
312×3=
1
3
+
1
3
=
4
5
-
1
5
=
5
7
+
2
7
=
3
6
+
2
6
=
7
10
-
5
10
+
3
10
=
答案

220+60=280,780-290=490,990+990=1980,55÷8=6…7,50×5=250,
73÷9=8…1,600×8=4800,37÷4=9…1,6×23=138,41×6=246,
312×3=936,
1
3
+
1
3
=
2
3
4
5
-
1
5
=
3
5
5
7
+
2
7
=1,
3
6
+
2
6
=
5
6
7
10
-
5
10
+
3
10
=
1
2

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