Bài 2: Trang 41 VBt toán 5 tập 1
Tính:
a) $\frac{1}{4}$ + $\frac{3}{8}$ + $\frac{5}{16}$ = ........................................
b) $\frac{3}{5}$ - $\frac{1}{3}$ - $\frac{1}{6}$ = .........................................
c) $\frac{4}{7}$ x $\frac{5}{8}$ x $\frac{7}{12}$ = .........................................
d) $\frac{25}{28}$ : $\frac{15}{14}$ x $\frac{6}{7}$ = .........................................
Bài Làm:
a) $\frac{1}{4}$ + $\frac{3}{8}$ + $\frac{5}{16}$ = $\frac{4}{16}$ + $\frac{6}{16}$ + $\frac{5}{16}$ = $\frac{15}{16}$
b) $\frac{3}{5}$ - $\frac{1}{3}$ - $\frac{1}{6}$ = $\frac{18}{30}$ - $\frac{10}{30}$ - $\frac{5}{30}$ = $\frac{3}{30}$ = $\frac{1}{10}$
c) $\frac{4}{7}$ x $\frac{5}{8}$ x $\frac{7}{12}$ = $\frac{20}{56}$ x $\frac{7}{12}$ = $\frac{140}{672}$ = $\frac{5}{24}$
d) $\frac{25}{28}$ : $\frac{15}{14}$ x $\frac{6}{7}$ = $\frac{25}{28}$ x $\frac{14}{15}$ x $\frac{6}{7}$ = $\frac{5\times \not{5}\times \not{2}\times \not{7}}{2 \times \not{2}\times \not{7}\times \not{5}\times 3}$ x $\frac{6}{7}$ = $\frac{5}{6}$ x $\frac{6}{7}$ = $\frac{5}{7}$