Visual Model 1
Question: Use the number line to find \(5+(-8)\).
- A. \(-13\)
- B. \(-3\)
- C. \(3\)
- D. \(13\)
Why it works: Start at \(5\) on a number line and move \(8\) units left. The result is \(5+(-8)=-3\).
Answer: \(-3\)
CH02-12 lesson
Integer Addition and Subtraction Learning Activity
A focused Grade 6 learning session for Integer Addition and Subtraction using visual models, worked examples, strategy guidance, and a short mastery check.
- 15
- minutes
- 6
- lesson parts
- 11
- practice items
Students will build Grade 6 mastery of integer addition and subtraction using models, equations, and test-style reasoning.
Student goal: I can solve problems involving integer addition and subtraction.
Helpful first:
Distance on the Coordinate Plane
Learn the Idea
Integer Addition and Subtraction means using place value, operations, and equations to reason accurately with numbers.
- Read the question carefully and identify what is being asked.
- Choose a model, equation, table, or diagram that matches the situation.
- Solve one step at a time and keep units or labels attached.
- Use the answer explanation to check that the result makes sense.
See the Math
Follow a Worked Example
Example 1
Question: A bank account starts at \($250\). After a withdrawal of \($100\), what is the new balance?
- A. \($150\)
- B. \($350\)
- C. \($100\)
- D. \(-$150\)
- Starting balance: \(250\).
- Withdrawal is \(-100\).
- So \(250+(-100)=150\).
Answer: \($150\)
Example 2
Question: The temperature at noon was \(5°\text{C}\). By evening, it dropped \(12°\text{C}\). Use the thermometer to find the evening temperature.
- A. \(7°\text{C}\)
- B. \(-17°\text{C}\)
- C. \(17°\text{C}\)
- D. \(-7°\text{C}\)
- Start at 5° and drop (subtract) 12°: \(5+(-12)=-7°\).
Answer: \(-7°\text{C}\)
Connect It to a Real Situation
Problem 1
Question: A hiker starts at elevation \(1{,}200\) feet and climbs to \(1{,}850\) feet. What is the change in elevation?
- A. \(650\) feet
- B. \(-650\) feet
- C. \(3{,}050\) feet
- D. \(1{,}200\) feet
Why it works: Change in elevation: \(1{,}850-1{,}200=650\) feet.
Answer: \(650\) feet
Avoid Mistakes and Choose a Strategy
- Rushing before identifying what the numbers represent.
- Choosing an operation that does not match the situation.
- Dropping labels, units, or context from the answer.
- Skipping the estimate or reasonableness check.
- Underline the question being asked.
- Use a model before jumping to computation.
- Write an equation that matches the story or picture.
- Explain the final answer in a sentence.
Remember the Key Idea
Integer Addition and Subtraction becomes easier when students connect the question to a model, use clear steps, and explain why the answer fits.
GOLDEN RULE
Understand the model before choosing the operation.
Solve before opening the answer
Use scratch paper. The explanation matters more than simply seeing whether the choice is correct.
warmup
2 questionsWhat is \(-7+3\)?
- A \(-10\)
- B \(-4\)
- C \(4\)
- D \(10\)
Check answer and explanation
Answer B: \(-4\)
Start at \(-7\) on a number line and move \(3\) units right: \(-7+3=-4\).
Use the number line to find \(5+(-8)\).
- A \(-13\)
- B \(-3\)
- C \(3\)
- D \(13\)
Check answer and explanation
Answer B: \(-3\)
Start at \(5\) on a number line and move \(8\) units left. The result is \(5+(-8)=-3\).
guided
1 questionWhich chip model shows \(-4+6\)? (Red chips = \(-1\), Blue chips = \(+1\))
- A Model A; answer is \(2\)
- B Model B; answer is \(2\)
- C Model A; answer is \(10\)
- D Model B; answer is \(8\)
Check answer and explanation
Answer A: Model A; answer is \(2\)
\(-4+6\): use 4 red and 6 blue chips. Pair and remove red-blue pairs. Result: 2 blue chips remaining, so \(-4+6=2\).
practice
5 questionsA bank account starts at \($250\). After a withdrawal of \($100\), what is the new balance?
- A \($150\)
- B \($350\)
- C \($100\)
- D \(-$150\)
Check answer and explanation
Answer A: \($150\)
Starting balance: \(250\). Withdrawal is \(-100\). So \(250+(-100)=150\).
The temperature at noon was \(5°\text{C}\). By evening, it dropped \(12°\text{C}\). Use the thermometer to find the evening temperature.
- A \(7°\text{C}\)
- B \(-17°\text{C}\)
- C \(17°\text{C}\)
- D \(-7°\text{C}\)
Check answer and explanation
Answer D: \(-7°\text{C}\)
Start at 5° and drop (subtract) 12°: \(5+(-12)=-7°\).
Show \(-5+(-3)\) on a number line.
- A Starts at \(-5\), ends at \(-8\), sum is \(-8\)
- B Starts at \(-5\), ends at \(-2\), sum is \(-2\)
- C Starts at \(0\), ends at \(-8\), sum is \(-8\)
- D Starts at \(-5\), ends at \(-3\), sum is \(-3\)
Check answer and explanation
Answer A: Starts at \(-5\), ends at \(-8\), sum is \(-8\)
\(-5+(-3)=-8\). Start at \(-5\) and move 3 units left, landing at \(-8\).
A golf player has a score of \(-5\) (5 under par). She then plays another hole and her score drops by \(2\) more strokes. What is her new total score?
- A \(-7\)
- B \(-3\)
- C \(3\)
- D \(7\)
Check answer and explanation
Answer A: \(-7\)
Starting score: \(-5\). Dropping 2 more means \(-5+(-2)=-7\).
Which number line correctly shows \(-4+6=2\)?
- A Arrow goes from \(-4\) right \(6\) to \(2\)
- B Arrow goes from \(-4\) left \(6\) to \(-10\)
- C Arrow goes from \(0\) right \(6\) to \(6\)
- D Arrow goes from \(4\) right \(6\) to \(10\)
Check answer and explanation
Answer A: Arrow goes from \(-4\) right \(6\) to \(2\)
Starting at \(-4\) and moving right \(6\) units: \(-4+6=2\).
exit
3 questionsUsing a chip model where red chips represent \(-1\) and blue chips represent \(+1\), what is the sum?
- A \(-1\)
- B \(1\)
- C \(5\)
- D \(-5\)
Check answer and explanation
Answer A: \(-1\)
Red chips = negative. Blue chips = positive. Three red chips = \(-3\). Two blue chips = \(+2\). Total: \(-3+2=-1\).
What is \(2+(-2)\)?
- A \(-4\)
- B \(0\)
- C \(2\)
- D \(4\)
Check answer and explanation
Answer B: \(0\)
A number and its opposite always sum to zero: \(2+(-2)=0\).
An elevator is at floor \(8\). It descends \(11\) floors. At which floor is the elevator now?
- A \(-3\)
- B \(3\)
- C \(19\)
- D \(-19\)
Check answer and explanation
Answer A: \(-3\)
Starting floor: \(8\). Descending 11 floors: \(8+(-11)=-3\).
