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Session 18: Addition and subtraction of fractions

Session Title

Addition and subtraction of fractions 

Objective
  1. Students will understand and solve addition and subtraction problems with like and unlike denominators.
  2. Students will represent and simplify fraction operations visually and numerically.
  3. Students will explore and identify equivalent fractions using fraction strips.

Concept

  • To understand how to add and subtract like and unlike denominators.

Materials Required
  1. Blackboard 
  2. Fraction manipulatives (circles, bars, or strips)
  3. Paper plates (for fraction pizza activity)
  4. Colored pencils or markers
  5. Pre-cut fraction cards (e.g., ½, ⅓, ¼, ⅙, etc.)

Methodology

  • Start with basic concepts of fractions

  • Provide clear step by step explanations and examples through activity.

Session Duration 

 90 Minutes

Introduction  Activity (30 minutes)

  • Fraction Strip Match-Up
  • Create Fraction Strips:
  • Give each student (or group) colored strips of paper.

Have them fold and cut the strips to show different fractions:

  • 1 strip = whole
  • Fold in 2 = halves
  • Fold in 3 = thirds
  • Fold in 4, 6, 8 = corresponding fractions

Label the Strips:

  • Students write the fraction name on each part of the strip (e.g., “1/2”, “1/4”).
  •  Explore Equivalents:
  • Students lay out their strips and compare lengths.
  • They find and stack strips that are the same total length. For example:
  • Place two 1/4 strips over one 1/2 strip to see they are equal.
  • Match three 1/6 strips to one 1/2 strip.

Record Discoveries:

On a worksheet, students write equivalent fraction pairs they find (e.g., 1/2 = 2/4 = 3/6).

Introduce addition and subtraction of fractions with the same denominator using fraction strips and real-world examples.

 Model a few problems on the board:

E.g., 2/5 + 1/5 = 3/5

E.g., 4/6 - 2/6 = 2/6

Then give some individual activity for students

Hook Question:

“Can we add 1/2 and 1/3 the way they are? Why or why not?”

Briefly discuss: The denominators are different — they don’t represent the same-sized parts.

Explain that we need like denominators (common denominator) to combine or compare.

Example 1: Convert 1/2 and 1/3

Find Least Common Denominator (LCD): 6

Convert:

1/2 = 3/6

1/3 = 2/6

Now: 3/6 + 2/6 = ⅚

Use fraction strips to show how 1/2 and 1/3 can be represented as sixths.

Example 2 (student practice):

Convert 3/4 and 2/3 to like fractions.

LCD = 12

3/4 = 9/12

2/3 = 8/12

Give students 1–2 practice problems to solve on whiteboards or in notebooks. Example:

Convert 2/5 and 1/2 to like fractions

Convert 5/6 and 1/4 to like fractions

Main Activity (35 minutes)

Ask: “Can we add 1/2 and 1/3 as they are?” (No)

Show visually with fraction strips that they are different-sized parts.

Explain: “To add or subtract fractions, we need to make the pieces the same size — we need a common denominator.”

Model with Visuals:

1/2 + 1/3

Find the Least Common Denominator (6)

Convert: 1/2 = 3/6, 1/3 = 2/6 → 3/6 + 2/6 = 5/6

"Fraction Friends Challenge"

1. Group students in pairs or small groups.

2. Each group gets a set of fraction cards and fraction strips.

3. Challenge: Pick two cards, find a common denominator, and solve.

Each person solves it on their own first.

Then compare answers and explain how they got it.

Use fraction strips to physically represent their answer and confirm visually

Review Questions

Follow-up Tasks (10 minutes)

  1. ½+3/3

  2. 4/8+6/4

  3. 5/10+3/2

Expected Learning  Outcome:

Knowledge building:

  • To understand how to add and subtract like fractions

  • Expert in the conversion of unlike fractions to like

  • To understand how to add and subtract unlike fractions.

Skill Building:

  • Collaborate with a peer

  • Respectful communication and empathy

  • Logical thinking

  • Problem solving

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