Question

Số?

a)12 x 4= ? x 12         (17x5)x2=17x(5x?)

106 x 3 =3 x ?             86x2x5=86 x(2x?)

b)7x ? =7             519 x ? =0              ? x0=0

432 x? =432          1x ? = 0                ?x1 =3456

Answer 1

a)

12 × 4 = 4 × 12

106 × 3 = 3 × 106

(17 × 5) × 2 = 17 × (5 × 2)

86 × 2 × 5 = 86 × (2 × 5)

b)

7 × 1 = 7

432 × 1 = 432

519 × 0 = 0

1 × 0 = 0

2 × 0 = 0

3 456 × 1 = 3 456