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小5算数 分数のいろいろな計算11

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分数のたし算ひき算,かけ算わり算を1問ずつ!

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<問題>

次の⑤~⑧の計算をしよう!

⑤ \(\displaystyle 3\frac{7}{3}+1\frac{3}{4}=\)

⑥ \(\displaystyle \frac{35}{6}÷15=\)

⑦ \(\displaystyle 3\frac{3}{4}-1.2=\)

⑧ \(\displaystyle 1\frac{5}{8}×28=\)

正解はこちら!

⑤ \(\displaystyle 3\frac{7}{3}+1\frac{3}{4}\)

\(\displaystyle =3\frac{7×4}{3×4}+1\frac{3×3}{4×3}\)

\(\displaystyle =3\frac{28}{12}+1\frac{9}{12}\)

\(\displaystyle =4\frac{37}{12}\)

\(\displaystyle =4\frac{1+12+12+12}{12}\)

\(\displaystyle =7\frac{1}{12}\)

⑥ \(\displaystyle \frac{35}{6}÷15\)

\(\displaystyle =\frac{35}{6×15}\)

\(\displaystyle =\frac{35}{90}\)

\(\displaystyle =\frac{7}{18}\)

⑦ \(\displaystyle 3\frac{3}{4}-1.2\)

\(\displaystyle =3\frac{3}{4}-\displaystyle \frac{12}{10}\)

\(\displaystyle =3\frac{3×5}{4×5}-\displaystyle \frac{12×2}{10×2}\)

\(\displaystyle =3\frac{15}{20}-\displaystyle \frac{24}{20}\)

\(\displaystyle =2\frac{15+20}{20}-\displaystyle \frac{24}{20}\)

\(\displaystyle =2\frac{35}{20}-\displaystyle \frac{24}{20}\)

\(\displaystyle =2\frac{11}{20}\)

⑧ \(\displaystyle 1\frac{5}{8}×28\)

\(\displaystyle =\frac{13}{8}×28\)

\(\displaystyle =\frac{13×28}{8}\)

\(\displaystyle =\frac{13×14}{4}\)

\(\displaystyle =\frac{13×7}{2}\)

\(\displaystyle =\frac{91}{2}\) ここで終わってもOK!

\(\displaystyle =45\frac{1}{2}\) 帯分数にしてもOK!

全問解けたでしょうか

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