Sec 1 Maths Chapter 2 Review

Integers, Rational Numbers and Real Numbers Summary and Review

Revise the key ideas from Chapter 2, including negative numbers, integer operations, fractions, decimals, rational numbers, irrational numbers and real numbers.

This page is designed for students preparing for a class test and teachers who need a structured review lesson with practice questions and answers.

Visual summary and review for integers rational numbers and real numbers in Sec 1 Maths
Chapter summary

What to revise

By the end of Chapter 2, students should be able to move confidently between number-line ideas, integer operations, fractions, decimals and number types.

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Negative numbersUnderstand numbers below zero using number lines, basements and real-life situations.
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Integer operationsAdd, minus, multiply and divide positive and negative integers.
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Combined operationsUse brackets first, then multiplication or division, then addition or minus.
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Fractions and decimalsConvert between forms and compare values carefully.
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Real numbersClassify integers, rational numbers, irrational numbers and real numbers.
Review 1

Integer operations review

Integer questions test whether students understand direction, sign rules and order of operations.

Add

Adding a positive number moves right or up. Adding a negative number moves left or down.

−4 + 7 = 3

5 + (−8) = −3

Minus

Minus can be pictured as moving down or left.

3 − 8 = −5

−6 − 4 = −10

Multiply and divide

Same signs give a positive answer. Different signs give a negative answer.

−6 × −2 = 12

24 ÷ −3 = −8

Key reminder: for multiplication and division, decide the sign first, then calculate the number part.
Review 2

Fractions and decimals review

Fractions, mixed numbers and decimals are different ways to show values. Students should be able to convert and compare them.

Skill Example What to remember
Simplify a fraction 12/18 = 2/3 Divide the numerator and denominator by the same common factor.
Convert a mixed number 2 3/5 = 13/5 Multiply the whole number by the denominator, then add the numerator.
Convert decimal to fraction 0.75 = 75/100 = 3/4 Use tenths, hundredths or thousandths, then simplify.
Convert fraction to decimal 3/8 = 0.375 Divide the numerator by the denominator, or convert to a familiar denominator.
Review 3

Rational, irrational and real numbers review

Real numbers include rational and irrational numbers. The main task is to recognise how the groups are related.

Integers

Whole numbers, zero and negative whole numbers.

Examples: −3, −1, 0, 4, 12

Rational numbers

Numbers that can be written as a fraction of two integers, where the denominator is not zero.

Examples: −2, 1/2, 0.25, 3

Irrational numbers

Numbers that cannot be written exactly as a fraction of two integers.

Examples: √2, √5, π

Important: all integers are rational numbers. All rational and irrational numbers are real numbers.
Common mistakes

Common mistakes to avoid

1. Comparing negative numbers wrongly

Students may think −8 is greater than −3 because 8 is greater than 3.

Correct: −8 is smaller than −3 because −8 is further left on the number line.

2. Forgetting operation order

Students may work from left to right even when multiplication appears after addition.

Correct: −3 + 4 × (−2)

= −3 + (−8)

= −11

3. Misusing sign rules

Students may forget that two negative signs in multiplication or division give a positive answer.

Correct: −6 × −5 = 30

4. Confusing integers and rational numbers

Students may think only fractions are rational numbers.

Correct: −4 is also rational because −4 = −4/1.

Review Exercise 2

Review Exercise questions

Try these questions after revising the chapter summary. They mix the main skills from Chapter 2.

Arrange in ascending order: −4, 2, −7, 0, 5.

Evaluate: −6 + 11

Evaluate: −3 − 8

Evaluate: −7 × 4

Evaluate: −42 ÷ −6

Evaluate: 5 − 3 × (−4)

Evaluate: 24 ÷ (−3) + 2 × 5

Simplify: 15/25

Convert 3 2/7 to an improper fraction.

Convert 0.6 to a fraction in simplest form.

Convert 5/8 to a decimal.

Classify −12 as integer, rational, irrational or real.

Classify √3 as rational or irrational.

Explain why 0.125 is a rational number.

A lift starts at B4. It goes up 9 floors, then down 3 floors. Which level does it reach?

Challenge questions

Challenge questions

These questions require students to combine ideas and explain their thinking.

Find the value of −2 × (5 − 9) + 18 ÷ (−3).

Arrange in ascending order: −1.5, 1/2, −2, 0.25, 0.

A number is rational but not an integer. Give two possible examples.

Explain why every integer is a rational number.

Explain why √7 is not a rational number.

Answers

Answers and explanations

Use these answers after students have attempted the review exercise and challenge questions.

Review Exercise answers

1. −7, −4, 0, 2, 5
2. 5
3. −11
4. −28
5. 7
6. 17
7. 2
8. 3/5
9. 23/7
10. 3/5
11. 0.625
12. −12 is an integer, rational number and real number.
13. √3 is irrational.
14. 0.125 = 125/1000 = 1/8, so it is rational.
15. B4 = −4. −4 + 9 − 3 = 2. It reaches Level 2.

Challenge answers

1. 5 − 9 = −4. −2 × −4 = 8. 18 ÷ −3 = −6. Answer: 2.
2. −2, −1.5, 0, 0.25, 1/2
3. Examples: 1/2, −3/4, 0.25, 2.5
4. Every integer can be written over 1. For example, −6 = −6/1.
5. √7 cannot be written exactly as a fraction of two integers.
Teacher notes

Teacher revision notes

Suggested lesson flow

1
Begin with the checklistAsk students to mark which areas feel confident and which need revision.
2
Review common mistakesUse the misconception section before giving the review exercise.
3
Attempt review exerciseLet students attempt independently before checking answers.
4
Use challenge questionsUse these for stronger students or class discussion.

Teacher prompts

Which number is further left on the number line?

Should the final answer be positive or negative?

Which operation must be done first?

Can this number be written as a fraction of two integers?

Is this number an integer, rational number, irrational number or real number?

Chapter 2 complete

Students should now have revised negative numbers, integer operations, fractions, decimals, rational numbers, irrational numbers and real numbers.

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