Tính bằng cách thuận tiện nhất. a) 1 235 × 6 789 × (630 – 315 × 2),....

a) 1 235 × 6 789 × (630 – 315 × 2)

= 1 235 × 6 789 × (630 – 630)

= 1 235 × 6 789 × 0

= 0

b) 14,25 + 5,88 + 35,75 + 16,12

= (14,25 + 35,75) + (5,88 + 16,12)

= 50 + 22

= 72

c) \(\frac{3}{5} \times \frac{1}{3} + \frac{3}{5} \times \frac{2}{3}\)

= \(\frac{3}{5} \times \,\,(\frac{1}{3} + \frac{2}{3})\)

= \(\frac{3}{5}\,\, \times \,\,1\)

= \(\frac{3}{5}\)

d) 6,48 + 3,72 + 7,52 + 4,28

= (6,48 +7,52) + (3,72+ 4,28)

= 14 + 8

= 22