Bài 2: Trang 12 VBT toán 5 tập 1
Chuyển các hỗn số thành phân số rồi thực hiện phép tính:
a) $2\frac{1}{8}$ + $1\frac{3}{4}$ = .....................
$3\frac{2}{7}$ + $1\frac{3}{7}$ = .....................
b) $5\frac{1}{3}$ - 2$\frac{5}{6}$ = ......................
$4\frac{7}{9}$ - $1\frac{5}{9}$ = ......................
c) $2\frac{4}{5}$ x $3\frac{1}{8}$ = ......................
$1\frac{1}{5}$ : $1\frac{4}{5}$ = ........................
Bài Làm:
a) $2\frac{1}{8}$ + $1\frac{3}{4}$ = $\frac{17}{8}$ + $\frac{7}{4}$ = $\frac{17}{8}$ + $\frac{14}{8}$ = $\frac{31}{8}$
$3\frac{2}{7}$ + $1\frac{3}{7}$ = $\frac{23}{7}$ + $\frac{10}{7}$ = $\frac{33}{7}$
b) $5\frac{1}{3}$ - 2$\frac{5}{6}$ = $\frac{16}{3}$ - $\frac{17}{6}$ = $\frac{32}{6}$ - $\frac{17}{6}$ = $\frac{15}{6}$ = $\frac{5}{2}$
$4\frac{7}{9}$ - $1\frac{5}{9}$ = $\frac{43}{9}$ - $\frac{14}{9}$ = $\frac{29}{9}$
c) $2\frac{4}{5}$ x $3\frac{1}{8}$ = $\frac{14}{5}$ x $\frac{25}{8}$ = $\frac{7\times \not{2}\times \not{5}\times 5}{\not{5}\times 4\times \not{2}}$ = $\frac{35}{4}$
$1\frac{1}{5}$ : $1\frac{4}{5}$ = $\frac{6}{5}$ : $\frac{9}{5}$ = $\frac{6}{5}$ x $\frac{5}{9}$ = $\frac{30}{45}$ = $\frac{2}{3}$