Adding and subtracting integers
Add and subtract positive and negative integers, including subtracting negative numbers.
Worked examples
Adding a negative integer
Straightforward
Problem
Calculate .
1
Locate the starting point on the number line.
Start at .
2
Adding a positive number means moving right along the number line.
Move places to the right from :
3
Read the result.
Answer
Subtracting a negative integer
Moderate
Problem
Calculate .
1
Apply the rule: subtracting a negative is the same as adding the positive.
2
Add the two positive integers.
Answer
Multi-step expression with mixed operations
Challenging
Problem
Calculate .
1
Rewrite the expression by replacing with .
2
Work from left to right. First add and .
3
Then add to the result.
Answer
Practise
Q1·Straightforward
Calculate .
Explanation
Starting at and moving places right:
Q2·Straightforward
Calculate .
Explanation
Adding is the same as subtracting :
Q3·Straightforward
Calculate .
Explanation
Starting at and moving places right:
Q4·Straightforward
Calculate .
Explanation
Subtracting means moving left on the number line:
Q5·Moderate
Calculate .
Explanation
Replace with :
Q6·Moderate
Calculate .
Explanation
Replace with :
Q7·Moderate
Calculate .
Explanation
Replace with :
Q8·Moderate
Calculate .
Explanation
Replace with :
Q9·Challenging
Calculate .
Explanation
Replace with :
Work left to right:
Work left to right:
Q10·Challenging
Calculate .
Explanation
Rewrite the expression:
Work left to right:
Work left to right:
Q11·Challenging
Calculate .
Explanation
Replace with :
Work left to right:
Work left to right:
Q12·Challenging
Calculate .
Explanation
Rewrite the expression:
Work left to right:
Work left to right: