( )5
乘以 4( )
------------------------
2( )5
1( )0
--------------------
( )6 4 ( )
( )5
乘以 4( )
------------------------
2( )5
1( )0
--------------------
( )6 4 ( )
(3)5
乘以 4(7)
------------------------
2( 4)5
1(4)0
--------------------
(1)6 4 (5)
(3) 5
X 4 (7)
—————
2 (4) 5
1(4)0
———————
1 6 4 5
35
x 47
--------------
245
140
------------
1645
(3 )5
x 4(7 )
------------------------
2(4 )5
1(4 )0
--------------------
(1 )6 4 (5 )
3
7
4
4
1 5