Number

Adding & Subtracting Integers

1

Positive, Negative or Zero?

Sort each integer into the correct column.

-7
4
0
-12
9
-1
100
-50
Negative
Zero
Positive
3

Match to the Number Line

Draw a line to match each description to its integer.

5 below zero
3 above zero
8 below zero
halfway between -2 and 2
0
-8
3
-5
5

Adding Integers

Circle the correct answer.

3 + (−5)

-2
8
-8

-4 + 7

3
-3
11

-6 + (−3)

-9
9
-3

−10 + 10

0
20
-20

-2 + (−8)

-10
10
6
6

Subtracting Integers

Circle the correct answer.

5 − 8

-3
3
13

-3 − 4

-7
7
-1

6 − (−2)

8
4
-8

-5 − (−3)

-2
2
-8
TipSubtracting is moving left on the number line. Subtracting a negative is moving right.
7

Integer Sequences

Fill in the missing integers.

-5
-3
-1
3
?
8
5
2
-4
?
-10
-6
-2
6
?
8

Match Temperature Changes

Match each situation to the correct result.

Temp was −3°C, rose 8°C
Temp was 5°C, fell 9°C
Temp was −6°C, fell 4°C
Temp was −2°C, rose 2°C
5°C
−4°C
−10°C
0°C
9

Integer Word Problems

Solve each problem and show your working.

The temperature in Canberra was −6°C at night. By midday it had risen 14°C. What was the midday temperature?

A submarine is at −80 m. It rises 35 m. What is its new depth?

Sam owes $25 and earns $40. How much does Sam have now?

11

Multiplying Integers

Same signs → positive. Different signs → negative. Circle the correct answer.

3 × (−4)

−12
12
−7

(−5) × (−2)

10
−10
−7

(−6) × 3

−18
18
−9

(−4) × (−4)

16
−16
−8
12

Dividing Integers

Apply the same sign rules. Circle the correct answer.

−20 ÷ 4

−5
5
−16

(−18) ÷ (−3)

6
−6
−15

15 ÷ (−5)

−3
3
−10

(−24) ÷ (−8)

3
−3
−16
16

BODMAS with Negative Numbers

Use order of operations. Circle the correct answer.

3 + 2 × (−4)

−5
−20
5

(−3)² − 10

−1
−19
1

−2 × (5 − 8)

6
−6
−26

4 − (−3) × 2

10
2
−2
17

Distance Between Integers

The distance between two integers equals |a − b|. Match each pair to their distance apart.

−3 and 5
−7 and −2
4 and −6
0 and −9
5
10
9
8
TipAbsolute value |n| is the distance from 0. Always non-negative.
18

Real-World Integer Problems

Write a calculation and solve each problem.

A diver is at −12 m. She descends a further 8 m. She then ascends 5 m. What is her final depth?

A bank account starts with $50. Five equal withdrawals of $18 are made. What is the balance? Is this an overdraft?

22

Integer Puzzles

Find the missing integer.

? + (−5) = −2. Find ?

? × (−3) = 12. Find ?

(−4) − ? = 1. Find ?

TipWork backwards from the answer. If ? + 3 = −1, then ? = −1 − 3 = −4.
23

Integer Expressions — Positive or Negative Result?

Sort each expression by the sign of its result.

-5 + 3
(-2) × (-4)
-6 + 6
3 - 8
(-3)²
0 × (-7)
Negative result
Zero
Positive result
TipCompute each one mentally before sorting.
26

Integer Sequences — Multiplying

Fill in the missing terms.

1
-2
4
16
?
-3
9
-27
243
?
-5
25
-125
?
TipThese sequences are made by repeatedly multiplying. Look for the common ratio.
27

Altitude Word Problems

Write integer calculations and solve.

A plane is at altitude 8000 m. It descends at 200 m per minute. Write an expression for its altitude after t minutes. What is its altitude after 30 minutes?

A lift starts at level −3 (basement). It goes up 8 levels, then down 5 levels. What level does it end at?

29

Comparing Negative Values

Circle the correct comparison.

−5 ○ −10

-5 > -10
-5 < -10
-5 = -10

|−8| ○ |5|

|−8| > |5|
|−8| < |5|
|−8| = |5|

−3² ○ (−3)²

-3² < (-3)²
-3² > (-3)²
-3² = (-3)²
31

Investigate Integer Patterns

Complete the pattern and explain the rule.

Calculate: (−1)¹, (−1)², (−1)³, (−1)⁴, (−1)⁵. Describe the pattern.

Calculate: (−2)¹, (−2)², (−2)³, (−2)⁴. What is the pattern of signs?

34

Integer Grid — Sums

In the 3×3 grid, fill in integers so that every row, column, and diagonal sums to the given value.

Fill a 3×3 grid using integers from -4 to 4 (each used once) so every row, column and diagonal sums to 0. Write your grid here.

Draw here

How many different solutions can you find?

TipThis is a magic square! For the sum 0, try: the centre should be 0. Opposite integers like 3 and -3 pair nicely.
35

Absolute Value — Order

Sort these integers in order from smallest absolute value to largest.

-8
3
-1
6
Smallest |n|
2nd
3rd
Largest |n|
Tip|n| is the distance from 0, regardless of sign. |−7| = 7 = |7|.
37

Integer Algebra — Substitution

Substitute the given integer value and evaluate.

If a = −3, find: (a) a² (b) 2a + 5 (c) a² − a

If x = −4 and y = 2, find: (a) xy (b) x − y (c) x² + y²

40

Integer Coordinates

Plot and describe points on a coordinate plane with negative values.

Plot these points on a coordinate plane: A(−3, 2), B(4, −1), C(−2, −4), D(0, 3). Label each quadrant.

Draw here

In which quadrant does the point (−5, −2) lie? Explain.

What is the distance from (−3, 0) to (5, 0)?

41

Quadrants

Match each point to its quadrant.

(3, 4)
(−2, 5)
(−1, −3)
(4, −2)
Quadrant IV
Quadrant I
Quadrant III
Quadrant II
TipQuadrant I: (+,+). Quadrant II: (−,+). Quadrant III: (−,−). Quadrant IV: (+,−).
42

Integer Properties

Circle the correct value.

(−8) + 8 =

0
16
-16
1

Any integer × 0 =

0
1
the integer
undefined

−(−(−5)) =

-5
5
0
15

|−12| − |8| =

4
-4
20
-20
43

Interpreting Negative Numbers in Graphs

A graph shows a diver's depth over time.

At t = 0, the diver is at −10 m. At t = 2, she is at −25 m. At t = 5, she is at −10 m. Describe what happened. Draw a sketch of the graph.

Draw here

What is the change in depth from t = 0 to t = 2?

What is the change in depth from t = 2 to t = 5?

46

Integer Magic Square

Create a magic square using nine consecutive integers.

Using integers −4, −3, −2, −1, 0, 1, 2, 3, 4, arrange them in a 3×3 grid so all rows, columns and diagonals sum to 0. Show your solution.

Draw here

If you added 5 to every integer in the grid, what would the new magic number be?

TipIn a magic square, all rows, columns and diagonals sum to the same 'magic number'. For integers −4 to 4, the magic number is 0.
47

Integer Expressions — Sort by Value

Sort these expressions from smallest to largest value.

(-3)²
-3²
(-2)³
Smallest
2nd
3rd
Largest
TipEvaluate each expression fully before sorting.
49

Solving Integer Puzzles with Algebra

Use algebra and integer operations.

The sum of three consecutive integers is −12. Find the integers.

When a number is multiplied by −3 and then 7 is added, the result is −5. Find the number.

51

Integers in Science — Subzero Temperatures

Use integer arithmetic to solve these science-based problems.

On Mars the temperature ranges from −125°C to 20°C. What is the range (difference)?

If it is −40°C outside and the windchill makes it feel 15°C colder, what is the apparent temperature?

The thermosphere reaches 2000°C. The stratosphere reaches −56°C. What is the difference?

53

Integer Sequences — Design Your Own

Create three different integer sequences and describe the rule for each.

Sequence 1 (arithmetic): Write the first 5 terms and state the rule.

Sequence 2 (geometric): Write the first 5 terms and state the rule.

Sequence 3 (your own pattern): Write the first 5 terms and state the rule.

TipTry arithmetic sequences (add a fixed amount), geometric sequences (multiply by a fixed amount), and a creative pattern of your own.
55

Integers and Binary Numbers

Computers represent negative numbers using a concept called two's complement.

In 4-bit binary, 0000 = 0, 0001 = 1, 0010 = 2, …, 0111 = 7. What does it mean if we use 1000 = −8, 1001 = −7, 1110 = −2, 1111 = −1? Write the values for 1010 and 1100.

Why would representing negative numbers be useful for a computer?

56

Create Your Own Integer Problem Set

Design a problem set for a younger student learning about integers.

Write two addition of integers problems with real-world context.

Write two multiplication of integers problems with answers.

Write one challenge word problem that requires multiple integer operations.

TipGood problems use real-world contexts (temperature, sea level, money) and include a range of difficulty.
58

Reflection: What I Know About Integers

Summarise your learning in your own words.

Explain in your own words why subtracting a negative number gives the same result as adding a positive number. Give an example.

Give three real-world contexts where negative integers naturally occur.

What is the most interesting thing you learned about integers? Why?

60

Integers at Home

Practise integers in real-world situations.

  • 1Track the daily temperature minimum and maximum for one week. Calculate daily ranges using subtraction.
  • 2Create a budget using integers: income as positive, expenses as negative. What is the net balance?
  • 3Play the game 24: use operations with four integers (some negative) to reach 24.
  • 4Watch the weather forecast and record temperatures. Identify which city had the coldest (most negative) temperature.