zbiory , liczby , wyrażenia   1 cała  i 3/4 * 2 całe i 2/5 1 cała i 1/4* 2/5   2 całe i 1/6 : 1 cała 2/5   3 całe i 1/7 - 4 całe i 2/9 1 cała 1/4 +2/5 2 całe i 3/4 - 1 cała i 2/5

[latex]1frac{3}{4}*2frac{2}{5}=frac{7}{4}*frac{12}{5}=frac{21}{5}=4frac{1}{5}\ 1frac{1}{4}*frac{2}{5}=frac{5}{4}*frac{2}{5}=frac{1}{2}\ 2frac{1}{6}:1frac{2}{5}=frac{13}{6}:frac{7}{5}=frac{13}{6}*frac{5}{7}=frac{65}{42}=1frac{23}{42}\ 3frac{1}{7}-4frac{2}{9}=3frac{9}{63}-4frac{14}{63}=-1frac{5}{63}[/latex] [latex]1frac{1}{4}+frac{2}{5}=1frac{5}{20}+frac{8}{20}=1frac{13}{20}\ 2frac{3}{4}-1frac{2}{5}=2frac{15}{20}-1frac{8}{20}=1frac{7}{20}[/latex]