Tài liệu Bai toan tinh nhanh phan so

TÝnh nhanh ph©n sè
Bµi 1: TÝnh nhanh:

15151515
31313131
454545
989898
−
=
101010115
101010131
1010145
1010198
x
x
x
x
−
=
45
98
-
15
31
=
45
98
-
45
93
=

45
6
= 2/15
Bµi 2: TÝnh nhanh:
151515
424242
143143
165165
2121
1313
)
951995199519
311931193119
19311931
19961996
1996
1995
)
××
××
b
a
VÝ dô 2:
199419961000
99619951996
×+
−×
( )
199419961000
)9961996(19941996

199419961000
996119941996
×+
−+×
=
×+
−+×
=
199419961000
100019941996
×+
+×
=
= 1(v× tö sè b»ng mÉu sè)
a) Tính nhanh:
1997 1998 1
1998 1996 1997
× −
× +
=
a)
199619971995
119961997
+×
−×
253399254
145399254
)
×+
−×

b
100219971995
99519961997
)
+×
−×
c
6960015392
593160015392
)
−×
×+
d
e)
199419951996
119971995
+×
−×
VÝ dô 3:
232323
242424
373737
535353
48
23
53
37
×××
2
1

48
24
48
24
1
23
24
48
23
37
53
53
37
23
24
37
53
48
23
53
37
1010123
1010124
1010137
1010153
48
23
53
37
==×=







××






×=
×××=
×
×
×
×
×
××=
Bµi 4: TÝnh nhanh:
2001
1001
2006
2004
2002
2008
2004
2001

2008
2006
)
5
7
200019991998
120011999
)
××××
×
×+
−×
b
a
Bµi 5: TÝnh nhanh
1000
99
1000
87
...
1000
49
1000
37
1000
25
1000
13
1000
1

+++++++
Bµi 4: Cho:
M =
39
37
...
15
13
11
9
7
5
3
1
×××××
N =
37
39
....
13
15
9
11
5
7
××××
H·y tÝnh M
×
N.