A number in mathematics is a value for measuring, counting, and labelling objects. The class 9 maths chapter 1 defines the number system, which is an important topic as the entire computer architecture, digital systems depend on the number system.
Fortunately, supplementing the CBSE pattern of studies is easy today. Several online guides offer solutions to student queries. For example, the MSVgo is an online learning app that makes learning easy through solutions mapped to the NCERT syllabus and CBSE board. A question bank of 10000+ questions, 15000+ videos, and interactive learning methods helps students learn concepts in minutes.
Topics in class 9 maths chapter 1
Numbers have several categories, like natural numbers, whole numbers, rational and irrational numbers and integers. Similarly, there are different types of number systems for performing various mathematical operations, each with specific properties.
1) Numbers
Natural numbers
Whole numbers
Integers
Rational number
Irrational number
Real number
Number symbol
2) Number System
Types of number systems
Number line
Decimal number system
Binary number system
Octal number system
Hexadecimal number system
Converting decimal to binary
Natural numbers
The numbers from 1 to infinity are called natural numbers such as 1, 2, 3... To infinity.
Whole Numbers
Whole numbers are a set of natural numbers plus the number 0. So the set of whole numbers looks like 0, 1,2,3,4, infinity.
Whole numbers stay on the right side of the number line from 0 and are positive in value. In other words, all the counting numbers are whole numbers.
Integers
Integers are whole numbers but can have a positive, negative or zero value. For example, 4, 31, 0,-22 are integers.
Rational Number
Rational numbers can be ratios like 1 / 2, 4 / 6 etc.
Irrational Number
Irrational numbers are real numbers that cannot be represented in the ratio form; for example, √5, √11.
Real Numbers
Every rational and irrational number are called a real number. Conceptually, every real number represents a unique point on the number line.
Number Symbol
N denotes natural numbers, I imaginary numbers, R Real numbers and Q, rational numbers.
You get irrational numbers (R-Q) by subtracting real numbers from rational numbers; the symbol Qᶦ is used for irrational numbers.
To learn more about number systems through simple, interactive, and explanatory visualizations, download the MSVgo app.