Common Core: 5th Grade Math : Add Fractions with Unlike Denominators

Study concepts, example questions & explanations for Common Core: 5th Grade Math

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Example Questions

Example Question #1 : Add Fractions With Unlike Denominators

\displaystyle \frac{1}{4}+\frac{1}{2}

Possible Answers:

\displaystyle \frac{2}{4}

\displaystyle \frac{2}{6}

\displaystyle \frac{3}{4}

\displaystyle \frac{1}{3}

\displaystyle \frac{1}{2}

Correct answer:

\displaystyle \frac{3}{4}

Explanation:

\displaystyle \frac{1}{4}+\frac{1}{2}

In order to solve this problem, we first have to find common denominators. 

\displaystyle \frac{1}{2}\times\frac{2}{2}=\frac{2}{4}

Now that we have common denominators, we can add the fractions. Remember, when we add and subtract fractions, we only add or subtract the numerator. 

\displaystyle \frac{1}{4}+\frac{2}{4}=\frac{3}{4}

Example Question #2 : Add Fractions With Unlike Denominators

\displaystyle \frac{1}{5}+\frac{1}{2}

Possible Answers:

\displaystyle \frac{1}{7}

\displaystyle \frac{7}{20}

\displaystyle \frac{2}{7}

\displaystyle \frac{8}{10}

\displaystyle \frac{7}{10}

Correct answer:

\displaystyle \frac{7}{10}

Explanation:

\displaystyle \frac{1}{5}+\frac{1}{2}

In order to solve this problem, we first have to find common denominators. 

\displaystyle \frac{1}{5}\times\frac{2}{2}=\frac{2}{10}

\displaystyle \frac{1}{2}\times \frac{5}{5}=\frac{5}{10}

Now that we have common denominators, we can add the fractions. Remember, when we add and subtract fractions, we only add or subtract the numerator. 

\displaystyle \frac{2}{10}+\frac{5}{10}=\frac{7}{10}

Example Question #3 : Add Fractions With Unlike Denominators

\displaystyle \frac{1}{3}+\frac{2}{5}

Possible Answers:

\displaystyle \frac{2}{8}

\displaystyle \frac{11}{30}

\displaystyle \frac{15}{11}

\displaystyle \frac{3}{8}

\displaystyle \frac{11}{15}

Correct answer:

\displaystyle \frac{11}{15}

Explanation:

\displaystyle \frac{1}{3}+\frac{2}{5}

In order to solve this problem, we first have to find common denominators. 

\displaystyle \frac{1}{3}\times\frac{5}5{}=\frac{5}{15}

\displaystyle \frac{2}{5}\times\frac{3}{3}=\frac{6}{15}

Now that we have common denominators, we can add the fractions. Remember, when we add and subtract fractions, we only add or subtract the numerator. 

\displaystyle \frac{5}{15}+\frac{6}{15}=\frac{11}{15}

Example Question #1 : Add Fractions With Unlike Denominators

\displaystyle \frac{1}{2}+\frac{2}{7}

Possible Answers:

\displaystyle \frac{3}{9}

\displaystyle \frac{11}{14}

\displaystyle \frac{1}{3}

\displaystyle \frac{14}{11}

Correct answer:

\displaystyle \frac{11}{14}

Explanation:

\displaystyle \frac{1}{2}+\frac{2}{7}

In order to solve this problem, we first have to find common denominators. 

\displaystyle \frac{1}{2}\times\frac{7}{7}=\frac{7}{14}

\displaystyle \frac{2}{7}\times\frac{2}{2}=\frac{4}{14}

Now that we have common denominators, we can add the fractions. Remember, when we add and subtract fractions, we only add or subtract the numerator. 

\displaystyle \frac{7}{14}+\frac{4}{14}=\frac{11}{14}

Example Question #2 : Add Fractions With Unlike Denominators

\displaystyle \frac{3}{4}+\frac{1}{3}=

Possible Answers:

\displaystyle 1\frac{1}{12}

\displaystyle \frac{12}{13}

\displaystyle \frac{7}{4}

\displaystyle \frac{13}{24}

\displaystyle \frac{4}{7}

Correct answer:

\displaystyle 1\frac{1}{12}

Explanation:

\displaystyle \frac{3}{4}+\frac{1}{3}

In order to solve this problem, we first have to find common denominators. 

\displaystyle \frac{3}{4}\times\frac{3}{3}=\frac{9}{12}

\displaystyle \frac{1}{3}\times\frac{4}{4}=\frac{4}{12}

Now that we have common denominators, we can add the fractions. Remember, when we add and subtract fractions, we only add or subtract the numerator. 

\displaystyle \frac{9}{12}+\frac{4}{12}=\frac{13}{12}

\displaystyle \frac{13}{12}=1\frac{1}{12} because \displaystyle 12 can go into \displaystyle 13 one time, with one left over. 

Example Question #4 : Add Fractions With Unlike Denominators

\displaystyle \frac{5}{6}+\frac{2}{4}

Possible Answers:

\displaystyle \frac{24}{16}

\displaystyle \frac{16}{24}

\displaystyle 1\frac{1}{3}

\displaystyle \frac{12}{16}

\displaystyle \frac{7}{10}

Correct answer:

\displaystyle 1\frac{1}{3}

Explanation:

\displaystyle \frac{5}{6}+\frac{2}{4}

In order to solve this problem, we first have to find common denominators. 

\displaystyle \frac{5}{6}\times\frac{2}{2}=\frac{10}{12}

\displaystyle \frac{2}{4}\times\frac{3}{3}=\frac{6}{12}

Now that we have common denominators, we can add the fractions. Remember, when we add and subtract fractions, we only add or subtract the numerator. 

\displaystyle \frac{10}{12}+\frac{6}{12}=\frac{16}{12}

\displaystyle \frac{16}{12}=1\frac{4}{12}=1\frac{1}{3} because \displaystyle 12 and go into \displaystyle 16 one time with four left over. \displaystyle \frac{4}{12} can be reduced to \displaystyle \frac{1}{3} by dividing the numerator and the denominator by \displaystyle 4

Example Question #5 : Add Fractions With Unlike Denominators

Solve the following:

\displaystyle \frac{2}{3}+\frac{1}{7}

Possible Answers:

\displaystyle \frac{17}{21}

\displaystyle \frac{16}{21}

\displaystyle \frac{3}{10}

\displaystyle \frac{1}{5}

\displaystyle \frac{17}{42}

Correct answer:

\displaystyle \frac{17}{21}

Explanation:

\displaystyle \frac{2}{3}+\frac{1}{7}

In order to solve this problem, we first have to find common denominators. 

\displaystyle \frac{2}{3}\times\frac{7}{7}=\frac{14}{21}

\displaystyle \frac{1}{7}\times\frac{3}{3}=\frac{3}{21}

Now that we have common denominators, we can add the fractions. Remember, when we add and subtract fractions, we only add or subtract the numerator. 

\displaystyle \frac{14}{21}+\frac{3}{21}=\frac{17}{21}

Example Question #656 : Number & Operations With Fractions

Solve:

\displaystyle \frac{2}{3}+\frac{1}2{}

Possible Answers:

\displaystyle \frac{6}{7}

\displaystyle \frac{7}{12}

\displaystyle \frac{3}{5}

\displaystyle 1\frac{1}{6}

\displaystyle \frac{5}{6}

Correct answer:

\displaystyle 1\frac{1}{6}

Explanation:

\displaystyle \frac{2}{3}+\frac{1}2{}

In order to solve this problem, we first have to find common denominators. 

\displaystyle \frac{2}{3}\times\frac{2}{2}=\frac{4}{6}

\displaystyle \frac{1}{2}\times\frac{}3{3}=\frac{3}{6}

Now that we have common denominators, we can add the fractions. Remember, when we add and subtract fractions, we only add or subtract the numerator. 

\displaystyle \frac{4}{6}+\frac{3}{6}=\frac{7}{6}

\displaystyle \frac{7}{6}=1\frac{1}{6} because \displaystyle 6 can go into \displaystyle 7 one time with \displaystyle \frac{1}{6} left over. 

Example Question #657 : Number & Operations With Fractions

Solve: 

\displaystyle \frac{1}{4}+\frac{4}{8}

Possible Answers:

\displaystyle \frac{3}{4}

\displaystyle \frac{5}{12}

\displaystyle \frac{8}{6}

\displaystyle \frac{12}5{}

\displaystyle \frac{1}{2}

Correct answer:

\displaystyle \frac{3}{4}

Explanation:

\displaystyle \frac{1}{4}+\frac{4}{8}

In order to solve this problem, we first have to find common denominators. 

\displaystyle \frac{1}{4}\times\frac{2}{2}=\frac{2}{8}

Now that we have common denominators, we can add the fractions. Remember, when we add and subtract fractions, we only add or subtract the numerator. 

\displaystyle \frac{2}{8}+\frac{4}{8}=\frac{6}{8}

\displaystyle \frac{6}{8}\div\frac{2}{2}=\frac{3}{4}

Example Question #658 : Number & Operations With Fractions

Solve:

\displaystyle \frac{4}6{+\frac{3}{8}}

Possible Answers:

\displaystyle 1\frac{1}{24}

\displaystyle \frac{25}{48}

\displaystyle \frac{24}{25}

\displaystyle \frac{1}{2}

\displaystyle \frac{7}{14}

Correct answer:

\displaystyle 1\frac{1}{24}

Explanation:

\displaystyle \frac{4}6{+\frac{3}{8}}

In order to solve this problem, we first have to find common denominators. 

\displaystyle \frac{4}{6}\times\frac{4}{4}=\frac{16}{24}

\displaystyle \frac{3}{8}\times\frac{3}{3}=\frac{9}{24}

Now that we have common denominators, we can add the fractions. Remember, when we add and subtract fractions, we only add or subtract the numerator. 

\displaystyle \frac{16}{24}+\frac{9}{24}=\frac{25}{24}

\displaystyle \frac{25}{24}=1\frac{1}{24} because \displaystyle 24 can go into \displaystyle 25 one time with \displaystyle 1 left over. 

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