CALCUL RÉFLÉCHI

+ 9 et – 9

Cache les résultats et entraîne-toi.

Ajouter 9, c’est ajouter 10 puis retirer 1                     C’est ajouter une dizaine puis retirer une unité

 

24 + 9=                                                                                                                                                               33

82 + 9 =                                                                                                                                                              9 1

26 + 9 =                                                                                                                                                              3 5

35 + 9 =                                                                                                                                                              4 4

46 + 9 =                                                                                                                                                              55

42 + 9 =                                                                                                                                                              5 1

35 + 9 =                                                                                                                                                              4 4

54 + 9 =                                                                                                                                                              6 3

45 + 9 =                                                                                                                                                              54

73 + 9 =                                                                                                                                                              82

Soustraire 9, c’est soustraire 10 puis ajouter 1                       c’est retirer une dizaine puis ajouter une unité

 

45 – 9 =                                                                                                                                                              36

56 – 9 =                                                                                                                                                              47

58 – 9 =                                                                                                                                                              49

69 – 9 =                                                                                                                                                              60

26 –9 =                                                                                                                                                               17

67 – 9 =                                                                                                                                                              58

96 – 9 =                                                                                                                                                              87

48 – 9 =                                                                                                                                                              39