In this Digital Logic lecture, you’ll clearly understand Number Systems (Binary, Octal, Decimal, Hexadecimal), base conversions, and the most important topic — r’s & (r–1)’s Complement. We’ll solve GATE PYQs step-by-step, cover shortcuts, and build concepts required for subtraction, arithmetic circuits, and computer architecture. Perfect for GATE 2025/2026, ESE, ISRO, BARC, DRDO, SSC JE, PSUs and all CS/IT, ECE, EE students. 📌 What’s Covered in This Video ✔ Number System Basics (Decimal, Binary, Octal, Hexadecimal) ✔ Base / Radix Concept Explained Clearly ✔ Number System Conversions (All Cases) ✔ r’s Complement Concept ✔ (r–1)’s Complement Concept ✔ Binary Complements: 1’s & 2’s Complement ✔ Decimal Complements: 9’s & 10’s Complement ✔ Subtraction Using Complements ✔ Signed Number Representation ✔ GATE PYQs (Fully Solved) ✔ Shortcuts & Exam-Friendly Tricks 🎯 Why This Topic Is Important One of the highest weightage topics in Digital Logic Directly asked every year in GATE, ESE & PSU exams Foundation of Arithmetic Circuits, ALU & Computer Architecture Essential for understanding subtraction & signed numbers Easy + Scoring topic if concepts are clear 🔥 SEO TAG PACK (Integrated + Natural) number system digital logic, r complement explained, r-1 complement explained, binary number system, decimal octal hexadecimal conversion, 1s and 2s complement, 9s and 10s complement, number system gate, digital logic number system, subtraction using complements, gate 2025 digital logic, cs it digital logic, ece digital electronics, number system pyq gate, signed number representation, arithmetic circuits, computer organization basics, codepect 📢 Hashtags #NumberSystem #rComplement #rMinus1Complement #DigitalLogic #Gate2025 #GateECE #GateCS #GateEE #DigitalElectronics #BooleanAlgebra #GatePreparation #Codepect #EngineeringStudents #GatePYQ