Skip to main content
Chapter 1 of 12
Flashcards

Number System

Gujarat Board · Class 9 · Mathematics

Flashcards for Number System — Gujarat Board Class 9 Mathematics. Quick Q&A cards covering key concepts, definitions, and formulas.

45 questions24 flashcards5 concepts
24 Flashcards
Card 1Rational Numbers

What is a rational number? Give the mathematical definition.

Answer

A number 'r' is called a rational number if it can be written in the form p/q, where p and q are integers and q ≠ 0. Examples: 1/2, -3/4, 5 (which is 5/1), 0 (which is 0/1).

Card 2Irrational Numbers

What is an irrational number? Give the definition and examples.

Answer

A number 's' is called irrational if it cannot be written in the form p/q, where p and q are integers and q ≠ 0. Examples: √2, √3, √15, π, 0.10110111011110...

Card 3Number Classification

True or False: Every integer is a rational number. Justify your answer.

Answer

True. Every integer m can be expressed in the form m/1, where both m and 1 are integers and 1 ≠ 0. Therefore, every integer is a rational number.

Card 4Decimal Expansions

What are the two types of decimal expansions that rational numbers can have?

Answer

Rational numbers have either: 1) Terminating decimal expansions (like 7/8 = 0.875), or 2) Non-terminating recurring (repeating) decimal expansions (like 1/3 = 0.333... = 0.3̄).

Card 5Decimal Expansions

What type of decimal expansion do irrational numbers have?

Answer

Irrational numbers have non-terminating non-recurring (non-repeating) decimal expansions. For example, √2 = 1.4142135... and π = 3.14159265...

Card 6Converting Decimals

Express 0.6̄ (0.666...) in the form p/q.

Answer

Let x = 0.6̄ = 0.666... 10x = 6.666... 10x = 6 + 0.666... = 6 + x 10x - x = 6 9x = 6 x = 6/9 = 2/3

Card 7Real Numbers

What is the collection of real numbers denoted by, and what does it include?

Answer

The collection of real numbers is denoted by R. It includes all rational numbers and all irrational numbers together. Every point on the number line represents a unique real number.

Card 8Operations on Real Numbers

If you add a rational number and an irrational number, what type of number do you get?

Answer

The sum of a rational number and an irrational number is always irrational. For example, 2 + √3 is irrational because √3 has a non-terminating non-recurring decimal expansion.

+16 more flashcards available

Practice All

Get detailed flashcards for Number System

Super Tutor gives you interactive content for every chapter of Gujarat Board Class 9 Mathematics — summaries, quizzes, flashcards, and more.

Try Super Tutor — It's Free

Frequently Asked Questions

What are the important topics in Number System for Gujarat Board Class 9 Mathematics?

Number System covers several key topics that are frequently asked in Gujarat Board Class 9 board exams. Focus on the core concepts listed on this page and practise related questions to build confidence.

Start by understanding all key concepts. Practise previous year questions from this chapter. Revise formulas and definitions regularly. Use flashcards for quick revision before the exam.

There are 24 flashcards for Number System covering key definitions, formulas, and concepts. Use them daily for 10–15 minutes for best results.

Sources & Official References

Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.