Bµi 1: TÝnh
a)
b) 578,69 + 281,78
594,72 + 406,38 - 329,47
5
3
3
2
+
12
1
7
2
12
7
+−
17
4
17
5
17
12
−−
Bµi 1: TÝnh
a)
b) 578,69 + 281,78 = 860,47
594,72 + 406,38 - 329,47 = 671,63
15
19
15
910
15
33
15
52
5
3
3
2
=
+
=
×
+
×
=+
21
8
84
32
84
72449
712
71
127
122
712
77
12
1
7
2
12
7
==
+−
=
×
×
+
×
×
−
×
×
=+−
17
3
17
4512
17
4
17
5
17
12
=
−−
=−−
Bµi 2: TÝnh b»ng c¸ch thuËn tiÖn nhÊt
a)
b)
c) 69,78 + 35,97 + 30,22
d) 83,45 - 30,98 - 42,47
4
1
11
4
4
3
11
7
+++
99
14
99
28
99
72
−−
Bµi 2: TÝnh b»ng c¸ch thuËn tiÖn nhÊt
a)
b)
c) 69,78 + 35,97 + 30,22 = (69,78+30,22)+35,97
= 100 + 35,97 = 135,97
d) 83,45 - 30,98 - 42,47 = 83,45 - (30,98 + 42,47)
= 83,45 - 73,45
= 10
211
4
4
11
11
4
1
4
3
11
4
11
7
4
1
11
4
4
3
11
7
=+=+=
++
+=+++
33
10
99
30
99
42
99
72
99
1428
99
72
99
14
99
28
99
72
==−=
+
−=−−