1.次の計算をしなさい。
(1)\(\displaystyle 2\frac{1}{10}×\frac{4}{7}×2\frac{1}{3}\)
\(\displaystyle \frac{14}{5}\)
(2)\(\displaystyle 3\frac{2}{3}×\frac{4}{7}×\frac{9}{22}\)
\(\displaystyle \frac{6}{7}\)
(3)\(\displaystyle \frac{5}{6}÷\frac{1}{3}÷\frac{5}{3}\)
\(\displaystyle \frac{3}{2}\)
(4)\(\displaystyle 3\frac{2}{3}÷2\frac{4}{9}÷1\frac{3}{4}\)
\(\displaystyle \frac{6}{7}\)
(5)\(\displaystyle \frac{8}{25}÷1\frac{1}{5}÷\frac{1}{9}\)
\(\displaystyle \frac{12}{5}\)
(6)\(\displaystyle \frac{7}{3}÷\frac{1}{3}×\frac{9}{14}\)
\(\displaystyle \frac{9}{2}\)
(7)\(\displaystyle \frac{4}{17}÷\frac{12}{17}×\frac{10}{3}\)
\(\displaystyle \frac{10}{9}\)
(8)\(\displaystyle \frac{1}{13}×\frac{3}{8}÷\frac{12}{13}\)
\(\displaystyle \frac{1}{32}\)
(9)\(\displaystyle 2\frac{1}{3}×\frac{9}{14}÷1\frac{1}{3}\)
\(\displaystyle \frac{9}{8}\)
(10)\(\displaystyle \frac{21}{16}×3\frac{1}{3}÷1\frac{7}{8}\)
\(\displaystyle \frac{7}{3}\)
(11)\(\displaystyle 1\frac{6}{7}÷\left(\frac{3}{2}+\frac{2}{3}\right)+1\frac{9}{14}\)
\(\displaystyle \frac{5}{2}\)
(12)\(\displaystyle 1\frac{1}{6}+\left(1\frac{3}{5}-1\frac{1}{3}\right)×2\frac{1}{2}\)
\(\displaystyle \frac{11}{6}\)
(13)\(\displaystyle 2\frac{2}{3}÷\left(1\frac{1}{3}+\frac{4}{5}\right)-\frac{1}{2}\)
\(\displaystyle \frac{3}{4}\)
(14)\(\displaystyle \frac{2}{7}+1\frac{5}{6}÷\left(2\frac{2}{5}+\frac{1}{6}\right)\)
\(\displaystyle 1\)
(15)\(\displaystyle 2\frac{1}{2}-1\frac{5}{9}×\left(\frac{10}{7}-\frac{2}{5}\right)\)
\(\displaystyle \frac{9}{10}\)
(16)\(\displaystyle 1.7+\frac{3}{2}\)
\(\displaystyle \frac{16}{5}\)
(17)\(\displaystyle 2\frac{3}{4}-1.25\)
\(\displaystyle \frac{3}{2}\)
(18)\(\displaystyle \frac{3}{5}+0.2-\frac{2}{3}\)
\(\displaystyle \frac{2}{15}\)
(19)\(\displaystyle 2.25-\frac{5}{12}+\frac{5}{6}\)
\(\displaystyle \frac{8}{3}\)
(20)\(\displaystyle 1.2+\frac{1}{6}-\frac{2}{3}\)
\(\displaystyle \frac{7}{10}\)
(21)\(\displaystyle \frac{2}{3}×1.8\)
\(\displaystyle \frac{6}{5}\)
(22)\(\displaystyle 2\frac{2}{5}÷1.2\)
\(\displaystyle 2\)
(23)\(\displaystyle \frac{5}{2}÷1.2÷\frac{3}{4}\)
\(\displaystyle \frac{25}{9}\)
(24)\(\displaystyle 1.3×3÷\frac{2}{5}\)
\(\displaystyle \frac{39}{4}\)
(25)\(\displaystyle \frac{5}{6}×1.4÷\frac{10}{27}\)
\(\displaystyle \frac{63}{20}\)
(26)\(\displaystyle 2\frac{1}{12}×\frac{2}{5}+2.5\)
\(\displaystyle \frac{10}{3}\)
(27)\(\displaystyle 4.6+\frac{4}{15}÷\frac{8}{7}\)
\(\displaystyle \frac{29}{6}\)
(28)\(\displaystyle 3\frac{13}{14}÷\frac{5}{2}-1.5\)
\(\displaystyle \frac{1}{14}\)
(29)\(\displaystyle 3\frac{1}{2}÷1.25÷\left(5\frac{1}{10}+0.5\right)\)
\(\displaystyle \frac{1}{2}\)
(30)\(\displaystyle \left(1\frac{1}{4}+\frac{3}{8}\right)÷1.5×2\frac{2}{3}\)
\(\displaystyle \frac{26}{9}\)
2.次の問いに答えなさい。
(1)縦が\(\displaystyle \frac{5}{8}\)cm、横が\(\displaystyle \frac{9}{10}\)cm、高さが\(\displaystyle \frac{4}{15}\)cmの直方体がある。この直方体の体積を答えなさい。
\(\displaystyle \frac{5}{8}×\frac{9}{10}×\frac{4}{15}=\frac{3}{20}\)
【答】\(\displaystyle \frac{3}{20}cm^3\)
(2)縦が\(\displaystyle \frac{8}{7}\)cm、横が\(\displaystyle \frac{5}{12}\)cm、体積が\(\displaystyle \frac{2}{9}\)cm\(^3\)の直方体がある。高さは何cmになるか答えなさい。
\(\displaystyle \frac{2}{9}÷\frac{8}{7}÷\frac{5}{12}=\frac{7}{15}\)
【答】\(\displaystyle \frac{7}{15}cm\)
(3)縦が\(\displaystyle \frac{7}{3}\)cm、高さが1.8cm、体積が2cm\(^3\)の直方体がある。この直方体の横の長さを求めなさい。
\(\displaystyle 2÷1.8÷\frac{7}{3}=\frac{10}{21}\)
【答】\(\displaystyle \frac{10}{21}cm\)
(4)国語の教科書の厚さは4.2cmです。算数の教科書の厚さは国語の教科書の\(\displaystyle \frac{6}{7}\)倍である。算数の教科書の厚さは何cmになるか答えなさい。
\(\displaystyle 4.2×\frac{6}{7}=\frac{18}{5}\)
【答】\(\displaystyle \frac{18}{5}cm\)
(5)青のリボンの長さは3.6mです。青のリボンは赤のリボンの長さの\(\displaystyle \frac{9}{20}\)倍である。赤のリボンの長さは何mになるか答えなさい。
\(\displaystyle 3.6÷\frac{9}{20}=8\)
【答】\(\displaystyle 8cm\)
(6)上底が\(\displaystyle \frac{6}{5}\)cm、下底が\(\displaystyle \frac{4}{3}\)cm、高さが1.5cmの台形の面積を求めなさい。
\(\displaystyle \left(\frac{6}{5}+\frac{4}{3}\right)×1.5÷2=\frac{19}{10}\)
【答】\(\displaystyle \frac{19}{10}cm^2\)