Question

1. Grupeaza convenabil factorii, pentru a calcula rapid:
2 x 3 x 5 =
7 x 2 x 5 =
8 x 4 x 2 =
4 x 12 x 0 =
2 x 7 x 2 =
3 x 5 x 2 =
10 x 5 x 2 =
1 x 9 x 10 =

Answer 1

(2×3)×5
7×(2×5)
8×(4×2)
4×(12×0)
7×(2×2)
3×(5×2)
2×(5×10)
10×(9×1)

Answer 2

1. (2x5)x3
2. (2x5)x7
3. (8x4)x2
4. (12x0) x4
5. (2x2)x7
6. (5x2)x3
7. (5x2)x10
10. (1x9)x10