分数の割り算/小学校6年生相当の算数/一般常識クイズ一問一答問題まとめ
問題
①\( \begin{array}{l} \dfrac{2}{5}\div 4 \end{array} \)
②\( \begin{array}{l} \dfrac{2}{3}\div \dfrac{7}{6} \end{array} \)
③\( \begin{array}{l} \dfrac{8}{7}\div \dfrac{4}{21} \end{array} \)
④\( \begin{array}{l} \dfrac{1}{9}\div \dfrac{7}{18} \end{array} \)
⑤\( \begin{array}{l} \dfrac{5}{6}\div \dfrac{15}{4} \end{array} \)
⑥\( \begin{array}{l} \dfrac{6}{7}\div \dfrac{54}{5} \end{array} \)
解法/ポイント
分数は逆数(分子と分母を逆)にしてかけ算にして計算しよう。
解答
①\( \begin{array}{l} \dfrac{2}{5}\div 4=\dfrac{2}{5}\times \dfrac{1}{4}=\dfrac{1}{10} \end{array} \)
②\( \begin{array}{l} \dfrac{2}{3}\div \dfrac{7}{6}=\dfrac{2}{3}\times \dfrac{6}{7}=\dfrac{4}{7} \end{array} \)
③\( \begin{array}{l} \dfrac{8}{7}\div \dfrac{4}{21}=\dfrac{8}{7}\times \dfrac{21}{4}=6 \end{array} \)
④\( \begin{array}{l} \dfrac{1}{9}\div \dfrac{7}{18}=\dfrac{1}{9}\times \dfrac{18}{7}=\dfrac{2}{7} \end{array} \)
⑤\( \begin{array}{l} \dfrac{5}{6}\div \dfrac{15}{4}=\dfrac{5}{6}\times \dfrac{4}{15}=\dfrac{4}{9} \end{array} \)
⑥\( \begin{array}{l} \dfrac{6}{7}\div \dfrac{54}{5}=\dfrac{6}{7}\times \dfrac{5}{54}=\dfrac{5}{63} \end{array} \)