口算天地.12+13=12-13=12×13=719×577=23-23×12=56×310=34×45=15×65=-数学

题文

口算天地.
1
2
+
1
3
=
1
2
-
1
3
=
1
2
×
1
3
=
7
19
×
57
7
=
2
3
-
2
3
×
1
2
=
5
6
×
3
10
=
3
4
×
4
5
=
1
5
×
6
5
=
题型:解答题  难度:中档

答案

1
2
+
1
3
=
5
6
1
2
-
1
3
=
1
6
1
2
×
1
3
=
1
6
7
19
×
57
7