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Great Inheritance Mathematics Term A · Independent learning

Multiplying a Fraction by a Whole Number

Learning target: Interpret repeated fractional groups and simplify the product.

Begin with the exact prerequisite checkpoint below. Afterward, explain why your strategy works, not merely which procedure to use.

Opening task

Explore · repeated fraction

Find 2 × 3/4 by thinking of 2 equal fractional groups.

Show answer and worked explanation

Answer: 1 1/2

How it works: Add 3/4 a total of 2 times, or multiply the numerator: (2×3)/4 = 3/2 = 1 1/2.

Prerequisite check (before instruction)

Attempt without help. A weak prerequisite signals review of 4A or 4B material, not a failed 5A lesson.

Show 3 × 1/4 using repeated addition.

Show answer and worked explanation

Answer: 1/4 + 1/4 + 1/4 = 3/4

How it works: Three copies of one fourth total three fourths.

Find 1/3 of 12 counters.

Show answer and worked explanation

Answer: 4 counters

How it works: Divide 12 into three equal groups; each group has 4 counters.

Lesson-specific prerequisite checkpoint

Do this without a worked example. If you cannot explain it, review the earlier skill before continuing.

Write 3 × 1/4 as an addition sentence.

Show answer and worked explanation

Answer: 1/4 + 1/4 + 1/4 = 3/4

How it works: Three identical quarter units are repeated.

Understand the idea

Interpret repeated fractional groups and simplify the product.

A fraction multiplied by a whole number can mean equal fractional groups repeated. Three groups of 2/5 are 2/5 + 2/5 + 2/5 = 6/5. Simplify improper products as mixed numbers when requested.

Vocabulary focus: fraction of a quantity, overlapping partitions, reciprocal. Make a small labeled model, work through the arithmetic, and explain the result in words.

Watch for: Confusing fraction times whole with fraction added to whole.

Model to study: Multiple repeated fractional strips.

Worked examples

Worked examples 1 · repeated fraction

Find 4 × 1/8 by thinking of 4 equal fractional groups.

Solution: 1/2

Why: Add 1/8 a total of 4 times, or multiply the numerator: (4×1)/8 = 1/2 = 1/2.

Worked examples 2 · repeated fraction

Find 6 × 4/6 by thinking of 6 equal fractional groups.

Solution: 4

Why: Add 4/6 a total of 6 times, or multiply the numerator: (6×4)/6 = 4 = 4.

Worked examples 3 · repeated fraction

Find 3 × 2/5 by thinking of 3 equal fractional groups.

Solution: 1 1/5

Why: Add 2/5 a total of 3 times, or multiply the numerator: (3×2)/5 = 6/5 = 1 1/5.

Check understanding

Check understanding 1 · repeated fraction

Find 5 × 3/5 by thinking of 5 equal fractional groups.

Show answer and worked explanation

Answer: 3

How it works: Add 3/5 a total of 5 times, or multiply the numerator: (5×3)/5 = 3 = 3.

Check understanding 2 · repeated fraction

Find 4 × 4/8 by thinking of 4 equal fractional groups.

Show answer and worked explanation

Answer: 2

How it works: Add 4/8 a total of 4 times, or multiply the numerator: (4×4)/8 = 2 = 2.

Guided practice

Guided practice 1 · repeated fraction

Find 4 × 2/4 by thinking of 4 equal fractional groups.

Show answer and worked explanation

Answer: 2

How it works: Add 2/4 a total of 4 times, or multiply the numerator: (4×2)/4 = 2 = 2.

Guided practice 2 · repeated fraction

Find 2 × 1/5 by thinking of 2 equal fractional groups.

Show answer and worked explanation

Answer: 2/5

How it works: Add 1/5 a total of 2 times, or multiply the numerator: (2×1)/5 = 2/5 = 2/5.

Guided practice 3 · repeated fraction

Find 4 × 3/4 by thinking of 4 equal fractional groups.

Show answer and worked explanation

Answer: 3

How it works: Add 3/4 a total of 4 times, or multiply the numerator: (4×3)/4 = 3 = 3.

Independent practice

Independent practice 1 · repeated fraction

Find 4 × 1/5 by thinking of 4 equal fractional groups.

Show answer and worked explanation

Answer: 4/5

How it works: Add 1/5 a total of 4 times, or multiply the numerator: (4×1)/5 = 4/5 = 4/5.

Independent practice 2 · repeated fraction

Find 2 × 4/8 by thinking of 2 equal fractional groups.

Show answer and worked explanation

Answer: 1

How it works: Add 4/8 a total of 2 times, or multiply the numerator: (2×4)/8 = 1 = 1.

Independent practice 3 · repeated fraction

Find 3 × 1/6 by thinking of 3 equal fractional groups.

Show answer and worked explanation

Answer: 1/2

How it works: Add 1/6 a total of 3 times, or multiply the numerator: (3×1)/6 = 1/2 = 1/2.

Independent practice 4 · repeated fraction

Find 4 × 2/3 by thinking of 4 equal fractional groups.

Show answer and worked explanation

Answer: 2 2/3

How it works: Add 2/3 a total of 4 times, or multiply the numerator: (4×2)/3 = 8/3 = 2 2/3.

Independent practice 5 · repeated fraction

Find 6 × 2/4 by thinking of 6 equal fractional groups.

Show answer and worked explanation

Answer: 3

How it works: Add 2/4 a total of 6 times, or multiply the numerator: (6×2)/4 = 3 = 3.

Challenge and error analysis

Challenge and error analysis 1 · worked-error diagnosis

Error-analysis notebook: Learner notebook (LESSON): “2 × 2/3 = 8/3. I added one fraction only once.” Identify exactly which written step or assumption fails, correct it, and independently solve this new task: Find 2 × 4/6 by thinking of 2 equal fractional groups.

Show answer and worked explanation

Answer: 1 1/3

How it works: Wrong step/assumption: Learner notebook (LESSON): “2 × 2/3 = 8/3. I added one fraction only once.” Diagnosis: Multiply fraction factors and overlap same-whole partitions; cancel only multiplicative factors, never terms joined by plus. Correct computation: Add 4/6 a total of 2 times, or multiply the numerator: (2×4)/6 = 4/3 = 1 1/3.

Challenge and error analysis 2 · reasoning transfer

Reasoning and transfer: Solve, then explain a different way to check your answer (inverse operation, estimate, model, or units as appropriate). Find 3 × 3/8 by thinking of 3 equal fractional groups.

Show answer and worked explanation

Answer: 1 1/8

How it works: Add 3/8 a total of 3 times, or multiply the numerator: (3×3)/8 = 9/8 = 1 1/8. Verification: show why the answer has a reasonable magnitude and matches the operation, referent and unit.

Exit check

Exit check 1 · repeated fraction

Find 3 × 5/6 by thinking of 3 equal fractional groups.

Show answer and worked explanation

Answer: 2 1/2

How it works: Add 5/6 a total of 3 times, or multiply the numerator: (3×5)/6 = 5/2 = 2 1/2.

Exit check 2 · repeated fraction

Find 5 × 2/8 by thinking of 5 equal fractional groups.

Show answer and worked explanation

Answer: 1 1/4

How it works: Add 2/8 a total of 5 times, or multiply the numerator: (5×2)/8 = 5/4 = 1 1/4.

Target for independent mastery: all exit-check problems correct plus a justified explanation. A instructor may reteach the concept if calculations are correct without meaningful reasoning.