Vở bài tập Toán lớp 5 Tập 2 trang 101 Chân trời sáng tạo

a) 3 526 + 709 + 81

b) 12,74 – 1,38 – 5,2

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c) $\frac{1}{3}-\frac{1}{6}+\frac{1}{12}$

d) $\frac{1}{3}-(\frac{1}{6}+\frac{1}{12})$

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a) 3 526 + 709 + 81

= 3 526 + (709 + 81)

= 3 526 + 790

= 4 316

c) $\frac{1}{3}-\frac{1}{6}+\frac{1}{12}$

$=\frac{4}{12}-\frac{2}{12}+\frac{1}{12}$

$=\frac{3}{12}$

$=\frac{1}{4}$

b) 12,74 – 1,38 – 5,2

= 11,36 – 5,2

= 6,16

d) $\frac{1}{3}-(\frac{1}{6}+\frac{1}{12})$

$=\frac{1}{3}-\left(\frac{2}{12}+\frac{1}{12}\right)$

$=\frac{1}{3}-\frac{3}{12}$

$=\frac{4}{12}-\frac{3}{12}$

$=\frac{1}{12}$