Grade 7 Mathematics Unit 2

Grade 7 Mathematics – Unit 2: Addition and Subtraction of Integers
Unit Overview

This unit introduces students to the addition and subtraction of integers, building on their understanding of whole numbers and extending it to include negative numbers. Students will explore real-life applications of integers, such as temperature changes, financial transactions, and elevation levels. Through guided discovery, interactive activities, and problem-solving exercises, learners will develop conceptual understanding and procedural fluency in integer operations.
Learning Objectives
By the end of this unit, students should be able to:
Define and identify integers on a number line.
Add integers using number lines and rules for signs.
Subtract integers using number lines and rules for subtraction.
Apply integer operations to solve real-world problems.
Check their answers using inverse operations.
Key Concepts
Integers: Whole numbers and their opposites (…, –3, –2, –1, 0, 1, 2, 3, …).
Addition of Integers:
Same signs → Add the absolute values, keep the common sign.
Example: (–3) + (–5) = –8
Different signs → Subtract the smaller absolute value from the larger one, keep the sign of the larger absolute value.
Example: (–7) + 3 = –4
Subtraction of Integers:
“Subtracting an integer is the same as adding its opposite.”
Example: 6 – (–4) = 6 + 4 = 10
Example: (–5) – 7 = (–5) + (–7) = –12
Classroom Activities
Activity 1: Integer Number Line Walk
Materials: Number line drawn on the floor, cards with integers.
Procedure:
A student starts at 0.
The teacher calls an integer (e.g., +3, –2).
The student walks right for positive and left for negative.
Discuss final positions and relate to addition/subtraction results.
Activity 2: Integer War Game
Materials: Deck of cards labeled –10 to +10.
Students draw two cards each and add or subtract them as instructed.
The student with the higher result wins the round.
Activity 3: Real-Life Scenarios
Students solve problems such as:
“The temperature dropped from 5°C to –3°C. What is the change?”
“You have $20, and you owe $15. What is your balance?”