-
10738
2013-05-03 07:12
504
3
1
2013.3
20 + 15 = 9 + 12 = 40 + 35 =
15 + 20 = 12 + 9 = 35 + 40 =
⒈
40 km 46 km
40+56=96km 56+40=96km
40+56=56+40
⒉
⒊
⒋
50
53
40 60
25 28
⒌
96 + 61 68 +29
⒍
+ = +
+ = +
a+b=b+a
⒎
⒏
⒐
⒑
a+b=a+b
( )
a+b=a+b
⑴ a+( )=b+( ) f + e =( )+( )
⑵ 307 + ( )= 348 +( ) . 123+847 = ( ) + ( )
⑶
⑷
⑸
115+ 132 128+ 85
⑹
37+45+63 91+50+109
⑴
⑵
⑴
⑵
-
2013-05-20
-
2013-05-04
-
2013-05-04
