d)
|
Calcule en trouvant un procédé simple. |
24
. 3 + 12 .
4 |
=
12 . 2 . 3 + 12 . 4 = 12 . 6 + 12 . 4 = 12 . (6 + 4) = 12 . 10 = 120 |
63
. 30 + 21 .
10 |
=
63 . 30 + 7 . 3 . 10 = 63 . 30 + 7 . 30 = 30 . (63 + 7) = 30 . 70 = 2100 |
75
. 12 + 50 .
32 |
=
25 . 3 . 12 + 25 . 2 . 32 = 25 . 36 + 25 . 64 = 25 . (36 + 64) = 25 . 100 = 2500 |