Tính (theo mẫu):
Mẫu: \(\displaystyle {2 \over 3}:5 = {2 \over {3 \times 5}} = {2 \over {15}}\)
a) \(\displaystyle {7 \over 8}:2\) b) \(\displaystyle {1 \over 2}:3\) c) \(\displaystyle {4 \over 3}:5\) d) \(\displaystyle {1 \over 3}:5\)
a) \(\displaystyle {7 \over 8}:2 = {7 \over {8 \times 2}} = {7 \over {16}}\) b) \(\displaystyle {1 \over 2}:3 = {1 \over {2 \times 3}} = {1 \over 6}\)
c) \(\displaystyle {4 \over 3}:5 = {4 \over {3 \times 5}} = {4 \over {15}}\) d) \(\displaystyle {1 \over 3}:5 = {1 \over {3 \times 5}} = {1 \over {15}}\)
-- Mod Toán lớp 4