5ème soutien opérations sur les fractions

5ème soutien opérations sur les fractions

5ème
SOUTIEN – OPERATIONS SUR LES FRACTIONS
EXERCICE 1 :
Calculer :
3
4
+
=
11
11
15
13
+
=
37
37
10
5
–
=
23 23
2,5 1,5
–
=
4
4
EXERCICE 2 :
Compléter :
4
….
10
+
=
7
7
7
1
6
7
+
=
…..
….
4
5 ….
3
–
=
= …..
3
3
….
12 ….
11
–
=
….
5
….
EXERCICE 3 :
Exprimer A, B, C et D sous la forme d’un nombre entier :
A=
1
1
+ =
2
2
B=
16 2
– =
7
7
C=
7
9
+ =
8
8
D=
7
5
+ =
3
3
EXERCICE 4 :
Calculer et donner le résultat sous la forme d’une fraction la plus simple possible :
A=
1
5
+ =
6
3
B=
10
5
+
=
11
33
C=
7
1
– =
12 3
D=
1
3
+ =
14
7
E=
5
5
–
=
4 12
F=
1
3
–
=
4 28
G=
4
77
–
=
75 25
H=
25
8
4
+ + =
21
7
3
I=
1
2
3
+ +
=
20
5
10
J=
1
+1=
5
K=1+
L=2–
1 1
– =
3 9
3
=
7
EXERCICE 5 :
Donner une écriture fractionnaire des produits :
A=
1 3
× =
2 4
B=
5
×3=
7
C=
11 9
× =
25 4
D=
2 4 8
× × =
7 5 3
EXERCICE 6 :
Compléter :
4 ….
8
×
=
7 ….
21
…. 5
35
× =
…. 4
32
5 …. 5
50
×
× =
3 …. 3
27
EXERCICE 7 :
Simplifier avant de calculer les produits suivants, on donnera le résultat sous la forme
d’une fraction la plus simple possible.
A=
1 6
× =
6 5
B=
17 13
8
×
×
=
13 15 17
C=
33
5
×
=
25 22
D=
28 20
×
=
15 21
E=
15 7 3
× × =
14 9 5
F=
26 11 14
×
×
=
35 13 22
5ème
CORRECTION DU SOUTIEN– OPERATIONS SUR LES FRACTIONS
EXERCICE 1 :
4
3
4+3
7
+
=
=
11
11
11
11
15
13
15 + 13
28
+
=
=
37
37
37
37
5
10 – 5
5
10
–
=
=
23 23
23
23
2,5 1,5
2,5 – 1,5
1
–
=
=
4
4
4
4
EXERCICE 2 :
6 10
4
+ =
7
7
7
1 6
7
+ =
4
4 4
5 2 3
– = =1
3 3 3
12 1 11
– =
5
5 5
EXERCICE 3 :
A=
1
1+1
2
1
+ =
= =1
2
2
2
2
B=
16 2
16 – 2
14
– =
=
=2
7
7
7
7
C=
7
9
7+9
16
+ =
=
=2
8
8
8
8
D=
7
5
7+5
12
+ =
=
=4
3
3
3
3
EXERCICE 4 :
A=
5
1
5×2
1
10
1 + 10
11
1
+ = +
= +
=
=
6
3
6
3×2
6
6
6
6
B=
10
5
10 × 3
5
30
5
30 + 5
35
+
=
+
=
+
=
=
11
33
11 × 3
33
33
33
33
33
C=
7
1
7
1×4
7
4
7–4
3
3×1
1
– =
–
=
–
=
=
=
=
12 3
12 3 × 4
12 12
12
12
3×4
4
D=
1
3
1
3×2
1
6
1+6
7
7×1
1
+ =
+
=
+
=
=
=
=
14
7
14 7 × 2
14
14
14
14
7×2
2
E=
5
5
5×3
5
15
5
15 – 5
10
5×2
5
–
=
–
=
–
=
=
=
=
4 12
4 × 3 12
12 12
12
12
6×2
6
F=
1
3
1×7
3
7
3
7–3
4
4×1
1
–
=
–
=
–
=
=
=
=
4 28
4 × 7 28
28 28
28
28
4×7
7
G=
77
4
77
4×3
77 12
77 – 12
65
5 × 13
13
–
=
–
=
–
=
=
=
=
75 25
75 25 × 3
75 75
75
75
5 × 15
15
25
8
4
25
8×3
4×7
25
24
28
25 + 24 + 28
+ + =
+
+
=
+
+
=
21
7
3
21
7×3
3×7
21
21
21
21
77
7 × 11
11
=
=
=
21
7×3
3
H=
1
2
3
1
2×4
3×2
1
8
6
1+8+6
15
+ +
=
+
+
=
+
+
=
=
20
5
10
20
5×4
10 × 2
20
20
20
20
20
3
5×3
=
=
4
5×4
I=
J=
1
1
1
1
1×5
1
5
1+5
6
+1= + = +
= + =
=
5
5
1
5
1×5
5
5
5
5
K=1+
L=2–
1 1
1
1 1
1×9
1×3 1
9
3 1
9+3–1
11
– = + – =
+
– = + – =
=
3 9
1
3 9
1×9
3×3 9
9
9 9
9
9
3
2 3
2×7 3
14 3
14 – 3
11
= – =
– =
– =
=
7
1 7
1×7 7
7
7
7
7
EXERCICE 5:
A=
1 3
1×3
3
× =
=
2 4
2×4
8
B=
5
5 3
5×3
15
×3= × =
=
7
7 1
7×1
7
C=
11 9
11 × 9
99
× =
=
25 × 4
100
25 4
D=
2 4 8
2×4×8
64
× × =
=
7 5 3
7×5×3
105
EXERCICE 6:
4 2
8
× =
7 3
21
7 5
35
× =
8 4
32
5 2 5
50
× × =
3 3 3
27
EXERCICE 7 :
A=
1 6
1×6
1
× =
=
6 5
6×5
5
B=
17 13
8
17 × 13 × 8
8
×
×
=
=
13 15 17
13 × 15 × 17
15
C=
5
33 × 5
3 × 11 × 5
3
33
×
=
=
=
25 × 22
5 × 5 × 2 × 11
10
25 22
D=
28 20
28 × 20
4×7×5×4
16
×
=
=
=
15 21
15 × 21
3×5×7×3
9
E=
15 7 3
15 × 7 × 3
5×3×7×3
1
× × =
=
=
14 9 5
14 × 9 × 5
7×2×3×3×5
2
F=
26 11 14
26 × 11 × 14
13 × 2 × 11 × 2 × 7
2
×
×
=
=
=
35 13 22
35 × 13 × 22
5 × 7 × 13 × 2 × 11
5