A focused Grade 5 learning session for Word Problems with Fraction Addition and Subtraction using visual models, worked examples, strategy guidance, and a short mastery check.
Student goal: I can solve word problems with fraction addition and subtraction.
Word Problems with Fraction Addition and Subtraction is the Grade 5 skill of students solve word problems involving addition and subtraction of fractions referring to the same whole. They use visual fraction models and equations to represent the problem and assess the reasonableness of answers using estimation.
Strong understanding comes from naming what the numbers, shapes, units, or data values represent, then showing the idea with a model or clear steps before solving.
The key to this topic is understanding the structure behind the work, not just following a rule. Students should be able to talk through what is happening, point to a model, and explain why the answer makes sense.
Question: A soup recipe calls for \(\frac{1}{6}\) cup of salt and \(\frac{2}{3}\) cup of water. Which amount is more?
How the model helps: Convert to common denominator 6: \(\frac{1}{6} = \frac{1}{6}\) and \(\frac{2}{3} = \frac{4}{6}\). Since \(\frac{4}{6} > \frac{1}{6}\), water is more.
Question: A recipe needs \(\frac{3}{5}\) cup of oil and \(\frac{2}{7}\) cup of vinegar. Which ingredient is more?
Answer: Oil is more
Question: Two containers hold \(\frac{1}{8}\) liter and \(\frac{3}{8}\) liter of juice. How much juice in total?
| Container | Amount (liters) |
|---|---|
| Container A | \(\frac{1}{8}\) |
| Container B | \(\frac{3}{8}\) |
| Total | ? |
Answer: \(\frac{1}{2}\) liter
Question: A recipe calls for \(\frac{2}{3}\) cup of sugar and \(\frac{1}{3}\) cup of flour. What is the total amount of dry ingredients measured?
Answer: \(1\) cup
Why it works: \(\frac{2}{3} + \frac{1}{3} = \frac{3}{3} = 1\) cup. Since the denominators are the same, add the numerators directly.
Word Problems with Fraction Addition and Subtraction gets easier when students read the model, track what each number means, and explain why the answer fits the situation.
Keep the whole consistent, show equal parts clearly, and explain what the fraction means.
Use scratch paper. The explanation matters more than simply seeing whether the choice is correct.
Miguel has \(\frac{3}{8}\) of a pizza and Rosa has \(\frac{2}{5}\) of a pizza of the same size. Who has more pizza?
Answer B: Rosa
To compare the fractions, change them to equivalent fractions with the same denominator. The least common denominator of \(8\) and \(5\) is \(40\). \( \frac{3}{8} = \frac{15}{40} \quadand\quad \frac{2}{5} = \frac{16}{40} \). Since \(16 > 15\), \(\frac{2}{5} > \frac{3}{8}\), so Rosa has more pizza.
Sarah ate \(\frac{1}{4}\) of a granola bar. Her brother ate \(\frac{1}{4}\) of the same bar. How much of the bar did they eat together?
Answer C: \(\frac{1}{2}\)
\(\frac{1}{4} + \frac{1}{4} = \frac{2}{4} = \frac{1}{2}\). Both ate equal amounts, so together they ate half the bar.
A recipe calls for \(\frac{2}{3}\) cup of sugar and \(\frac{1}{3}\) cup of flour. What is the total amount of dry ingredients measured?
Answer C: \(1\) cup
\(\frac{2}{3} + \frac{1}{3} = \frac{3}{3} = 1\) cup. Since the denominators are the same, add the numerators directly.
Tom jogged \(\frac{3}{5}\) of a mile on Monday and \(\frac{1}{5}\) of a mile on Tuesday. How far did he jog in total?
Answer C: \(\frac{4}{5}\) mile
\(\frac{3}{5} + \frac{1}{5} = \frac{4}{5}\) mile. Add numerators when denominators match.
A paint can is \(\frac{5}{6}\) full. If \(\frac{2}{6}\) is used to paint a door, how much paint remains?
Answer C: \(\frac{1}{2}\)
\(\frac{5}{6} - \frac{2}{6} = \frac{3}{6} = \frac{1}{2}\). Subtract the numerators when denominators are the same, then simplify.
Ella has \(\frac{7}{8}\) of a yard of ribbon. She uses \(\frac{3}{8}\) for a gift. How much ribbon does she have left?
Answer B: \(\frac{1}{2}\)
\(\frac{7}{8} - \frac{3}{8} = \frac{4}{8}\). This simplifies to \(\frac{1}{2}\) yard of ribbon.
A class fills a water jug. One container holds \(\frac{1}{2}\) of the jug and another container holds \(\frac{1}{2}\) of the same jug. Together, how much do they hold?
Answer C: \(1\) full jug
\(\frac{1}{2} + \frac{1}{2} = 1\). Two equal halves make one whole.
Marcus reads \(\frac{2}{10}\) of a book on Monday and \(\frac{5}{10}\) on Tuesday. What fraction does he read in total?
Answer C: \(\frac{7}{10}\)
\(\frac{2}{10} + \frac{5}{10} = \frac{7}{10}\) of the book.
A recipe uses \(\frac{3}{4}\) cup of milk. If you reduce it by \(\frac{1}{4}\) cup, how much milk do you use?
Answer B: \(\frac{1}{2}\) cup
\(\frac{3}{4} - \frac{1}{4} = \frac{2}{4} = \frac{1}{2}\) cup.
A craft project requires \(\frac{5}{12}\) of a piece of string and then \(\frac{4}{12}\) more. How much string is used total?
Answer C: \(\frac{9}{12}\)
\(\frac{5}{12} + \frac{4}{12} = \frac{9}{12} = \frac{3}{4}\) of the string.
A soup recipe calls for \(\frac{1}{6}\) cup of salt and \(\frac{2}{3}\) cup of water. Which amount is more?
Answer D: Water is more
Convert to common denominator 6: \(\frac{1}{6} = \frac{1}{6}\) and \(\frac{2}{3} = \frac{4}{6}\). Since \(\frac{4}{6} > \frac{1}{6}\), water is more.
