Vở bài tập Toán lớp 5 Tập 2 trang 99 Chân trời sáng tạo

a) (398 + 436) + 564

= ...........................................

= ...........................................

= ...........................................

$\frac{1}{6}+(\frac{5}{11}+\frac{5}{6})$

= ...........................................

= ...........................................

= ...........................................

(2,72 + 14,54) + 7,28

= ...........................................

= ...........................................

= ...........................................

b) 181 + 810 + 190 + 919

= ...........................................

= ...........................................

= ...........................................

$\frac{1}{3}+\frac{3}{14}+\frac{10}{15}+\frac{3}{14}$

= ...........................................

= ...........................................

= ...........................................

57,25 + 64,36 + 5,64 + 42,75

= ...........................................

= ...........................................

= ...........................................

a) (398 + 436) + 564

= 398 + (436 + 564)

= 398 + 1 000

= 1 398

 $\frac{1}{6}+(\frac{5}{11}+\frac{5}{6})$

= $(\frac{1}{6}+\frac{5}{6})+\frac{5}{11}$

= 1 + $\frac{5}{11}$

= $\frac{16}{11}$

(2,72 + 14,54) + 7,28

= (2,72 + 7,28) + 14,54

= 10 + 14,54

= 24,54

b) 181 + 810 + 190 + 919

= (181 + 919) + (810 + 190)

= 1 100 + 1 000

= 2100

$\frac{1}{3}+\frac{3}{14}+\frac{10}{15}+\frac{3}{14}$

= $(\frac{1}{3}+\frac{10}{15})+(\frac{3}{14}+\frac{3}{14})$

= $\left(\frac{5}{15}+\frac{10}{15}\right)+\frac{6}{14}$

= 1 + $\frac{3}{7}$

= $\frac{10}{7}$

57,25 + 64,36 + 5,64 + 42,75

= (57,25 + 42,75) + (64,36 + 5,64)

= 100 + 70

= 170