CH05-03 lesson

Multiplying Fractions by Fractions Learning Activity

A focused Grade 5 learning session for Multiplying Fractions by Fractions using visual models, worked examples, strategy guidance, and a short mastery check.

18
minutes
6
lesson parts
11
practice items
Learning goal

Students will multiply fractions by fractions using visual models and area reasoning.

Student goal: I can multiply fractions by fractions.

concept

Learn the Idea

Multiplying Fractions by Fractions is the Grade 5 skill of students multiply a fraction by a fraction, understanding the product (a/b) × (c/d) = ac/bd. They use area models to visualize the multiplication and understand why the product is smaller than either factor when both are less than 1.

What does the fraction represent, and how does the model prove it?

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.

  • Identify the whole first so every fraction part keeps the same meaning.
  • Use equal parts, number lines, or area models to show the relationship.
  • Check whether the answer should be larger, smaller, or equivalent before finishing.
  • Use the topic language from class discussions: Students multiply a fraction by a fraction, understanding the product (a/b) × (c/d) = ac/bd. They use area models to visualize the multiplication and understand why the product is smaller than either factor when both are less than 1.
visual model

See the Math

Visual Model 1

Question: The area model below shows \(\frac{1}{2} \times \frac{3}{4}\). What fraction is shaded (overlap region)?

Grade 5 Multiplying Fractions by Fractions figure 1

  • A. \(\frac{3}{8}\)
  • B. \(\frac{3}{6}\)
  • C. \(\frac{2}{8}\)
  • D. \(\frac{1}{2}\)

How the model helps: The rectangle is divided into 8 equal parts (4 columns \(\times\) 2 rows). The overlap covers 3 of those 8 parts, so \(\frac{1}{2}\times\frac{3}{4}=\frac{3}{8}\).

worked example

Follow a Worked Example

Example 1

Question: The rectangle model shows the overlapping shaded region for \(\frac{3}{5} \times \frac{2}{3}\). What fraction of the whole rectangle is overlapped?

Grade 5 Multiplying Fractions by Fractions figure 3

  • A. \(\frac{6}{15}=\frac{2}{5}\)
  • B. \(\frac{3}{5}\)
  • C. \(\frac{2}{3}\)
  • D. \(\frac{15}{6}\)
  1. The rectangle has 15 equal cells.
  2. The overlap covers 6 cells, so the product is \(\frac{6}{15}=\frac{2}{5}\).

Answer: \(\frac{6}{15}=\frac{2}{5}\)

Example 2

Question: Area model for \(\frac{3}{4} \times \frac{1}{2}\). The shaded (overlap) region represents what fraction?

Grade 5 Multiplying Fractions by Fractions figure 4

  • A. \(\frac{3}{8}\)
  • B. \(\frac{3}{6}\)
  • C. \(\frac{4}{8}\)
  • D. \(\frac{1}{2}\)
  1. Total cells: \(4 \times 2 = 8\).
  2. Shaded cells: 3.
  3. Overlap is \(\frac{3}{8}\).

Answer: \(\frac{3}{8}\)

real world

Connect It to a Real Situation

Problem 1

Question: A recipe calls for \(\frac{2}{3}\) cup of flour. You want to make \(\frac{1}{2}\) of the recipe. How much flour do you need?

  • A. \(\frac{2}{5}\) cup
  • B. \(\frac{1}{3}\) cup
  • C. \(\frac{3}{5}\) cup
  • D. \(1\) cup

Answer: \(\frac{1}{3}\) cup

Why it works: \(\frac{1}{2} \times \frac{2}{3} = \frac{2}{6} = \frac{1}{3}\) cup.

strategy

Avoid Mistakes and Choose a Strategy

  • Starting the computation before identifying what the numbers, units, or parts represent.
  • Combining numerators and denominators without first checking whether the fraction pieces match in size.
  • Forgetting to estimate, which makes it easier to miss an unreasonable answer.
  • Stopping at a number without explaining what the answer means in context.
  • Read the situation slowly and name what each number or label represents.
  • Draw fraction bars, area models, or number lines so equal parts stay visible.
  • Estimate first so you already know the answer's approximate size.
  • Check the answer with an inverse operation, another representation, or a sentence explanation.
  • Say the math idea out loud in simple words before writing the final answer.
summary

Remember the Key Idea

Multiplying Fractions by Fractions gets easier when students read the model, track what each number means, and explain why the answer fits the situation.

GOLDEN RULE

Keep the whole consistent, show equal parts clearly, and explain what the fraction means.

Guided to independent practice

Solve before opening the answer

Use scratch paper. The explanation matters more than simply seeing whether the choice is correct.

warmup

2 questions
G5-C04-T02-Q001 About 1 min

What is \(\frac{2}{3} \times \frac{1}{4}\)?

  1. A \(\frac{2}{7}\)
  2. B \(\frac{1}{12}\)
  3. C \(\frac{2}{12}\) or \(\frac{1}{6}\)
  4. D \(\frac{3}{4}\)
Check answer and explanation

Answer C: \(\frac{2}{12}\) or \(\frac{1}{6}\)

Multiply the numerators and denominators: \(\frac{2}{3}\times\frac{1}{4}=\frac{2}{12}\). Since both 2 and 12 can be divided by 2, the product simplifies to \(\frac{1}{6}\).

G5-C04-T02-Q002 About 1 min

Multiply: \(\frac{1}{2} \times \frac{1}{3}\)

  1. A \(\frac{1}{5}\)
  2. B \(\frac{1}{6}\)
  3. C \(\frac{2}{5}\)
  4. D \(\frac{1}{3}\)
Check answer and explanation

Answer B: \(\frac{1}{6}\)

Multiply numerators and denominators: \(\frac{1 \times 1}{2 \times 3} = \frac{1}{6}\).

guided

1 question
G5-C04-T02-Q003 About 1 min

The area model below shows \(\frac{1}{2} \times \frac{3}{4}\). What fraction is shaded (overlap region)?

Multiplying a Fraction by a Fraction visual for G5-C04-T02-Q003
  1. A \(\frac{3}{8}\)
  2. B \(\frac{3}{6}\)
  3. C \(\frac{2}{8}\)
  4. D \(\frac{1}{2}\)
Check answer and explanation

Answer A: \(\frac{3}{8}\)

The rectangle is divided into 8 equal parts (4 columns \(\times\) 2 rows). The overlap covers 3 of those 8 parts, so \(\frac{1}{2}\times\frac{3}{4}=\frac{3}{8}\).

practice

5 questions
G5-C04-T02-Q004 About 1 min

Multiply: \(\frac{2}{3} \times \frac{3}{4}\)

  1. A \(\frac{5}{7}\)
  2. B \(\frac{1}{2}\)
  3. C \(\frac{6}{7}\)
  4. D \(\frac{8}{12}\)
Check answer and explanation

Answer B: \(\frac{1}{2}\)

\(\frac{2}{3} \times \frac{3}{4} = \frac{2 \times 3}{3 \times 4} = \frac{6}{12}\), which simplifies to \(\frac{1}{2}\).

G5-C04-T02-Q005 About 1 min

What is \(\frac{3}{4} \times \frac{2}{5}\) in simplest form?

  1. A \(\frac{7}{20}\)
  2. B \(\frac{3}{10}\)
  3. C \(\frac{5}{9}\)
  4. D \(\frac{6}{9}\)
Check answer and explanation

Answer B: \(\frac{3}{10}\)

\(\frac{3}{4} \times \frac{2}{5} = \frac{6}{20} = \frac{3}{10}\) (divide by 2).

G5-C04-T02-Q006 About 1 min

The shaded overlap represents \(\frac{2}{3} \times \frac{2}{5}\). What fraction of the whole rectangle is shaded?

Multiplying a Fraction by a Fraction visual for G5-C04-T02-Q006
  1. A \(\frac{4}{8}\)
  2. B \(\frac{6}{8}\)
  3. C \(\frac{4}{15}\)
  4. D \(\frac{1}{2}\)
Check answer and explanation

Answer C: \(\frac{4}{15}\)

The rectangle has 15 cells (5 columns \(\times\) 3 rows). The shaded overlap region is 4 cells out of 15, so \(\frac{4}{15}\).

G5-C04-T02-Q007 About 1 min

Multiply \(\frac{2}{3} \times \frac{3}{4}\). Which choice shows the product in simplest form?

  1. A \(\frac{5}{7}\)
  2. B \(\frac{6}{7}\)
  3. C \(\frac{8}{12}\)
  4. D \(\frac{1}{2}\)
Check answer and explanation

Answer D: \(\frac{1}{2}\)

Multiply the numerators and denominators: \(\frac{2}{3}\times\frac{3}{4}=\frac{6}{12}\). Since 6 is half of 12, \(\frac{6}{12}=\frac{1}{2}\).

G5-C04-T02-Q008 About 1 min

Sarah has \(\frac{3}{4}\) of a pound of chocolate. She uses \(\frac{1}{3}\) of it to make brownies. How much chocolate does she use?

  1. A \(\frac{3}{12}\) pounds or \(\frac{1}{4}\) pounds
  2. B \(\frac{3}{16}\) pounds
  3. C \(\frac{2}{3}\) pounds
  4. D \(1\) pound
Check answer and explanation

Answer A: \(\frac{3}{12}\) pounds or \(\frac{1}{4}\) pounds

\(\frac{1}{3} \times \frac{3}{4} = \frac{3}{12} = \frac{1}{4}\) pound.

exit

3 questions
G5-C04-T02-Q009 About 1 min

Multiply: \(\frac{1}{4} \times \frac{1}{5}\)

  1. A \(\frac{1}{9}\)
  2. B \(\frac{2}{9}\)
  3. C \(\frac{1}{20}\)
  4. D \(\frac{1}{1}\)
Check answer and explanation

Answer C: \(\frac{1}{20}\)

\(\frac{1}{4} \times \frac{1}{5} = \frac{1}{20}\) (multiply numerators and denominators).

G5-C04-T02-Q010 About 1 min

The rectangle model shows the overlapping shaded region for \(\frac{3}{5} \times \frac{2}{3}\). What fraction of the whole rectangle is overlapped?

Multiplying a Fraction by a Fraction visual for G5-C04-T02-Q010
  1. A \(\frac{6}{15}=\frac{2}{5}\)
  2. B \(\frac{3}{5}\)
  3. C \(\frac{2}{3}\)
  4. D \(\frac{15}{6}\)
Check answer and explanation

Answer A: \(\frac{6}{15}=\frac{2}{5}\)

The rectangle has 15 equal cells. The overlap covers 6 cells, so the product is \(\frac{6}{15}=\frac{2}{5}\).

G5-C04-T02-Q011 About 1 min

Multiply: \(\frac{2}{5} \times \frac{2}{3}\)

  1. A \(\frac{4}{8}\)
  2. B \(\frac{5}{8}\)
  3. C \(\frac{4}{15}\)
  4. D \(\frac{2}{3}\)
Check answer and explanation

Answer C: \(\frac{4}{15}\)

\(\frac{2}{5} \times \frac{2}{3} = \frac{2 \times 2}{5 \times 3} = \frac{4}{15}\).

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