Class 9 Computer Applications (CBSE 165 & ICSE)
“Computers, the office tools, cyber safety, Python and Java — from the ground up”
The complete Class 9 Computer Applications course for both boards. CBSE (Code 165): how computers work, software & networks, cyber safety, the Office tools (Word, Spreadsheets, Presentations) and a first taste of Python. ICSE: the foundations of Java programming — OOP ideas, the JVM, classes & objects, data types, operators, input, the Math class, decisions, loops and ethics. Clear notes, worked code and chapter tests. Free forever.
🧪 Simulators
Convert number systems and flip logic gates live — don't just read the truth table, build it.
🐍 Real Python
Run Python in the browser, no install — see variables and loops execute step by step.
🇮🇳 Bilingual
Explanations in English and Hindi, tuned to the CBSE 083 syllabus.
📝 Exam-ready
CBSE theory, chapter tests and projects mapped to the 70+30 marks pattern.
CBSE Unit 1 · Basics of IT
How a computer works: its components, memory & storage, I/O devices, software types, networks and multimedia.
Basics of IT
Characteristics of a computer; the components (CPU, memory, storage, I/O); primary (RAM/ROM) vs secondary memory; storage and input/output devices.
System vs application software; network types (PAN/LAN/MAN/WAN); wired & wireless (Wi-Fi, Bluetooth); cloud computing; and multimedia elements.
CBSE Unit 2 · Cyber Safety
Stay safe online: secure browsing, passwords, privacy, digital footprint, cyberstalking and malware.
CBSE Unit 3 · Office Tools
Get productive: word processing, presentations and spreadsheets — formatting, formulas and charts.
Office Tools
Create, format and structure documents: text & paragraph formatting, headers/footers, find & replace, pictures & shapes, tables, and track changes.
Build slide shows: layouts & views, titles/text/backgrounds, headers/footers, images & sound, and animations & transitions.
Worksheets & workbooks, data entry & autofill, formatting, formulas & cell references, statistical functions (SUM/AVERAGE/MAX/MIN/IF) and charts.
CBSE Unit 4 · Coding Intro
A first taste of programming with Scratch and Python — run real Python live.
ICSE · Java Foundations
The ICSE Computer Applications syllabus — object-oriented Java from first principles.
Foundations
Procedure-oriented vs object-oriented programming, and the four pillars: abstraction, inheritance, polymorphism and encapsulation.
Applets vs applications, the compilation process (source→bytecode→machine), the JVM, and Java's salient features.
Object-Oriented Programming
Modelling real entities; class as a blueprint & object factory; message passing; objects as state + behaviour; class as a user-defined type.
Character set (ASCII/Unicode), escape sequences, Java tokens, constants & variables, the 8 primitive types with sizes, reference types, and type conversion.
Unary/binary/ternary operators; arithmetic, relational, logical, assignment and increment/decrement; prefix vs postfix; precedence & associativity; new and dot operators.
Initialisation/parameterised/run-time input; importing java.util; the Scanner methods (nextInt, nextDouble, next, nextLine, charAt); error types; comments; print vs println.
The java.lang Math class: pow, sqrt, cbrt, ceil, floor, round, abs, max, min, random — and turning maths formulas into Java expressions.
Control Structures
if, if-else, if-else-if ladder and nested if; switch-case with break/default and fall-through; menu-driven programs; System.exit(0).
Why loops; entry- vs exit-controlled (for/while vs do-while); inter-conversion; finite/infinite/delay loops; break vs continue.
Nested loops; printing patterns (rectangles, triangles); mathematical series; and classic number programs (prime, perfect, Fibonacci, Armstrong, palindrome).