才塾　定期テスト対策

$\begin{eqnarray*} \require{cancel} &&54\times(26+15)\div18\\ &=&54\times41\div18\\ &=&\cfrac{{}^3\bcancel{54}\times41}{\bcancel{18}}\\ &=&123 \end{eqnarray*}$

類題

$4462\div46$

答え　 $97$

類題

$323.7\div83$

答え　 $3.9$

類題

$5.41-1.65$

答え　 $3.76$

類題

$7-4.59$

答え　 $2.41$

類題

$0.3\times0.5$

答え　 $0.15$

類題

$4.3\times6.7$

答え　 $28.81$

類題

$58.824\div6.84$

答え　 $8.6$

類題

$\boxed{\large{\ 2\ }}$ 約分をしましょう。

$\cfrac{16}{64}$

答え　 $\cfrac{1}{4}$

類題

$\cfrac{36}{180}$

答え　 $\cfrac{1}{5}$

類題

$\boxed{\large{\ 3\ }}$ 計算をしましょう。

$3\cfrac{3}{8}+2\cfrac{5}{6}$

答え　 $6\cfrac{5}{24} \left(\cfrac{149}{24}\right)$

$\begin{eqnarray*} &&3\cfrac{3}{8}+2\cfrac{5}{6}\\ &=&3\cfrac{9}{24}+2\cfrac{20}{24}\\ &=&5\cfrac{29}{24}\\ &=&6\cfrac{5}{24} \end{eqnarray*}$

類題

$5-1\cfrac{5}{14}$

答え　 $\cfrac{51}{14} \left(3\cfrac{9}{14}\right)$

$\begin{eqnarray*} &&5-1\cfrac{5}{14}\\ &=&\cfrac{5}{1}-\cfrac{19}{14}\\ &=&\cfrac{70}{14}-\cfrac{19}{14}\\ &=&\cfrac{51}{14} \end{eqnarray*}$

類題

$\cfrac{25}{42}\times\cfrac{14}{45}$

答え　 $\cfrac{5}{27}$

$\begin{eqnarray*} &&\cfrac{25}{42}\times\cfrac{14}{45}\\ &=&\cfrac{{}^5\bcancel{25}}{{}^3\bcancel{42}}\times\cfrac{\bcancel{14}}{{}^9\bcancel{45}}\\ &=&\cfrac{5}{27} \end{eqnarray*}$

類題

$\cfrac{36}{65}\div4\cfrac{2}{13}$

答え　 $\cfrac{2}{15}$

$\begin{eqnarray*} &&\cfrac{36}{65}\div4\cfrac{2}{13}\\ &=&\cfrac{36}{65}\div\cfrac{54}{13}\\ &=&\cfrac{36}{65}\times\cfrac{13}{54}\\ &=&\cfrac{{}^2\bcancel{36}}{{}^5\bcancel{65}}\times\cfrac{\bcancel{13}}{{}^3\bcancel{54}}\\ &=&\cfrac{2}{15} \end{eqnarray*}$

類題

$59\div128\times256$

答え　 $118$

$\begin{eqnarray*} &&59\div128\times256\\ &=&\cfrac{59\times{}^2\bcancel{256}}{\bcancel{128}}\\ &=&118 \end{eqnarray*}$

類題

$\cfrac{5}{6}\div \cfrac{8}{9}\times \cfrac{9}{10}$

答え　 $\cfrac{27}{32}$

$\begin{eqnarray*} &&\cfrac{5}{6}\div \cfrac{8}{9}\times \cfrac{9}{10}\\ &=&\cfrac{5}{6}\times \cfrac{9}{8}\times \cfrac{9}{10}\\ &=&\cfrac{27}{32} \end{eqnarray*}$

類題

$2-1\cfrac{1}{11}\div\cfrac{54}{55}$

答え　 $\cfrac{8}{9}$

$\begin{eqnarray*} &&2-1\cfrac{1}{11}\div\cfrac{54}{55}\\ &=&2-\cfrac{12}{11}\div\cfrac{54}{55}\\ &=&2-\cfrac{12}{11}\times\cfrac{55}{54}\\ &=&2-\cfrac{{}^2\bcancel{12}}{\bcancel{11}}\times\cfrac{{}^5\bcancel{55}}{{}^9\bcancel{54}}\\ &=&\cfrac{2}{1}-\cfrac{10}{9}\\ &=&\cfrac{18}{9}-\cfrac{10}{9}\\ &=&\cfrac{8}{9} \end{eqnarray*}$

類題

答え

$\boxed{\large{\ 1\ }}①56②26③26④117⑤123⑥97\\ ⑦3.9⑧3.76⑨2.41⑩0.15⑪28.81⑫8.6\\ \boxed{\large{\ 2\ }}①\cfrac{1}{4}②\cfrac{1}{5}\\ \boxed{\large{\ 3\ }}①6\cfrac{5}{24} \left(\cfrac{149}{24}\right)②\cfrac{51}{14} \left(3\cfrac{9}{14}\right)③\cfrac{5}{27}\\ ④\cfrac{2}{15} ⑤118⑥\cfrac{27}{32}⑦\cfrac{8}{9}$

◀

▶