Карточки по теме: Сложение и вычитание дробей с разными знаменателями Карточка №1 Вычислить: 1) $$38\frac{1}{8}+14\frac{3}{24}$$ 2) $$11\frac{5}{9}-9\frac{7}{18}$$ 3) $$54\frac{15}{27}+16\frac{5}{3}$$ 4) $$5\frac{15}{20}-2\frac{27}{38}$$ 5) $$5\frac{7}{18}-0,25+\frac{1}{9}$$ 6) $$63,58-0,25+44$$ Карточка №2 Вычислить: 1) $$28\frac{5}{9}+19\frac{3}{4}$$ 2) $$27\frac{13}{30}-15\frac{7}{40}$$ 3) $$17\frac{2}{3}-15\frac{5}{28}$$ 4) $$19\frac{9}{21}-5,6$$ 5) $$13\frac{7}{15}-\frac{1}{6}-0,1$$ 6) $$56-1,56+17,5$$

Решим примеры из карточки №1: 1) $$38\frac{1}{8}+14\frac{3}{24}$$ $$38\frac{1}{8}+14\frac{1}{8}=38\frac{1}{8}+14\frac{1}{8}=(38+14)+(\frac{1}{8}+\frac{1}{8})=52+\frac{2}{8}=52\frac{1}{4}$$ 2) $$11\frac{5}{9}-9\frac{7}{18}$$ $$11\frac{10}{18}-9\frac{7}{18}=(11-9)+(\frac{10}{18}-\frac{7}{18})=2+\frac{3}{18}=2\frac{1}{6}$$ 3) $$54\frac{15}{27}+16\frac{5}{3}$$ $$54\frac{5}{9}+16\frac{5}{3}=54\frac{5}{9}+16\frac{15}{9}=(54+16)+(\frac{5}{9}+\frac{15}{9})=70+\frac{20}{9}=70+2\frac{2}{9}=72\frac{2}{9}$$ 4) $$5\frac{15}{20}-2\frac{27}{38}$$ $$5\frac{570}{760}-2\frac{540}{760}=(5-2)+(\frac{570}{760}-\frac{540}{760})=3+\frac{30}{760}=3\frac{3}{76}$$ 5) $$5\frac{7}{18}-0,25+\frac{1}{9}$$ $$5\frac{7}{18}-\frac{1}{4}+\frac{1}{9}=5\frac{14}{36}-\frac{9}{36}+\frac{4}{36}=5+\frac{14-9+4}{36}=5+\frac{9}{36}=5+\frac{1}{4}=5,25$$ 6) $$63,58-0,25+44$$ $$63,58-0,25+44=63,33+44=107,33$$ Решим примеры из карточки №2: 1) $$28\frac{5}{9}+19\frac{3}{4}$$ $$28\frac{20}{36}+19\frac{27}{36}=(28+19)+(\frac{20}{36}+\frac{27}{36})=47+\frac{47}{36}=47+1\frac{11}{36}=48\frac{11}{36}$$ 2) $$27\frac{13}{30}-15\frac{7}{40}$$ $$27\frac{52}{120}-15\frac{21}{120}=(27-15)+(\frac{52}{120}-\frac{21}{120})=12+\frac{31}{120}=12\frac{31}{120}$$ 3) $$17\frac{2}{3}-15\frac{5}{28}$$ $$17\frac{56}{84}-15\frac{15}{84}=(17-15)+(\frac{56}{84}-\frac{15}{84})=2+\frac{41}{84}=2\frac{41}{84}$$ 4) $$19\frac{9}{21}-5,6$$ $$19\frac{3}{7}-5,6=19\frac{3}{7}-5\frac{6}{10}=19\frac{3}{7}-5\frac{3}{5}=19\frac{15}{35}-5\frac{21}{35}=(19-5)+(\frac{15}{35}-\frac{21}{35})=14-\frac{6}{35}=13\frac{35}{35}-\frac{6}{35}=13\frac{29}{35}$$ 5) $$13\frac{7}{15}-\frac{1}{6}-0,1$$ $$13\frac{7}{15}-\frac{1}{6}-\frac{1}{10}=13\frac{14}{30}-\frac{5}{30}-\frac{3}{30}=13+\frac{14-5-3}{30}=13+\frac{6}{30}=13+\frac{1}{5}=13,2$$ 6) $$56-1,56+17,5$$ $$56-1,56+17,5=54,44+17,5=71,94$$