Bài 2 trang 16 SGK Toán 5

Đề bài

Tính:

\(a)\,\frac{5}{8} - \frac{2}{5};\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,b)\,1\frac{1}{{10}} - \frac{3}{4};\,\,\,\,\,\,\,\,\,\,\,\,\,\) \(c)\,\frac{2}{3} + \frac{1}{2}\, - \frac{5}{6}\)

Hướng dẫn giải

a) \( \frac{5}{8}-\frac{2}{5}=\frac{25}{40}-\frac{16}{40}=\frac{9}{40}\)

b)\(\,1\frac{1}{{10}} - \frac{3}{4} = \frac{{11}}{{10}} - \frac{3}{4} = \frac{{22}}{{20}} - \frac{{15}}{{20}} = \frac{7}{{20}}\)

c)\(\,\frac{2}{3} + \frac{1}{2}\, - \frac{5}{6} = \frac{4}{6} + \frac{3}{6} - \frac{5}{6} = \frac{{4 + 3 - 5}}{6} \) \(= \frac{2}{6} = \frac{1}{3} \)