अब मैं Lesson 4: Spreadsheet (LibreOffice Calc) का Full Ultimate Revision Sheet बना देता हूँ। इसमें 50+ Quick Points + Functions + Formulas + Shortcuts + Diagram Ideas होंगे, ताकि पूरा chapter एक नजर में याद किया जा सके।

---

📘 अध्याय 4: Spreadsheet (LibreOffice Calc) – Ultimate Revision Sheet

---

1️⃣ Spreadsheet क्या है?

• Spreadsheet एक software application है जो data को rows और columns में organize करता है।
• Calculations, Data Analysis, Reporting के लिए उपयोग होता है।

---

2️⃣ LibreOffice Calc परिचय

• Free & Open Source Spreadsheet software
• Excel जैसे काम करता है
• File formats: .ods, .xls, .xlsx, .csv

---

3️⃣ Workbook & Worksheet

• Workbook: एक file जिसमें कई worksheets हो सकती हैं
• Worksheet: Rows × Columns का grid structure

---

4️⃣ Rows & Columns

• Row: Horizontal (1,2,3…)
• Column: Vertical (A,B,C…)
• Cell = Row × Column

---

5️⃣ Cell Basics

• Active Cell – Select की गई Cell
• Cell Reference – A1, B2, C3…
• Input: Numbers, Text, Formula

---

6️⃣ Formulas & Functions

• Formulas: =A1+B1, =A1*B1
• Functions: SUM, AVERAGE, MAX, MIN, COUNT, IF

---

7️⃣ Relative & Absolute References

• Relative: =A1+B1 → Copy करने पर adjust होगा
• Absolute: =$A$1+$B$1 → Copy करने पर नहीं बदलेगा

---

8️⃣ Basic Arithmetic Operations

• Addition: =A1+B1
• Subtraction: =A1-B1
• Multiplication: =A1*B1
• Division: =A1/B1

---

9️⃣ Common Functions

• SUM(range), AVERAGE(range), MAX(range), MIN(range), COUNT(range), IF(condition,value_if_true,value_if_false)

---

🔟 Text Functions

• LEFT(text,n), RIGHT(text,n), CONCATENATE(A1,B1)

---

1️⃣1️⃣ Date & Time Functions

• TODAY(), NOW(), DATE(year, month, day)

---

1️⃣2️⃣ Logical Functions

• IF(condition, value_if_true, value_if_false)

---

1️⃣3️⃣ Lookup Functions

• VLOOKUP, HLOOKUP

---

1️⃣4️⃣ Mathematical Functions

• ROUND(number,n), INT(number), ABS(number)

---

1️⃣5️⃣ Statistical Functions

• AVERAGE, MAX, MIN, COUNT

---

1️⃣6️⃣ Cell Formatting

• Font, Color, Background, Borders
• Alignment: Left, Center, Right
• Number format: Currency, Date, Percentage

---

1️⃣7️⃣ Conditional Formatting

• Highlight cells based on criteria
• Example: Values >100 in red

---

1️⃣8️⃣ Data Validation

• Restrict input to numbers, dates, text length
• Example: Only numbers 1–100

---

1️⃣9️⃣ AutoFill

• Quickly fill sequences: numbers, dates, text

---

2️⃣0️⃣ Merge & Split Cells

• Merge multiple cells
• Split merged cells

---

2️⃣1️⃣ Row & Column Operations

• Insert/Delete Row & Column
• Resize Row Height / Column Width

---

2️⃣2️⃣ Sheet Management

• Insert / Delete Sheet
• Rename, Move, Copy Sheet

---

2️⃣3️⃣ Freeze Rows / Columns

• Keep headers visible
• View → Freeze Rows / Columns

---

2️⃣4️⃣ Hyperlinks in Calc

• Link to external websites or internal sheets
• Insert → Hyperlink

---

2️⃣5️⃣ Sorting & Filtering

• Sort Ascending / Descending
• Standard Filter & AutoFilter

---

2️⃣6️⃣ Pivot Tables

• Summarize and analyze large datasets
• Insert → Pivot Table

---

2️⃣7️⃣ Charts / Graphs

• Insert → Chart: Column, Bar, Line, Pie
• Customize Axis, Labels, Colors, Legend, Title

---

2️⃣8️⃣ Data Grouping & Outlines

• Group rows/columns for better organization
• Collapse / Expand sections

---

2️⃣9️⃣ Track Changes & Comments

• Collaborative editing
• Track changes and add comments

---

3️⃣0️⃣ Sheet Linking

• Reference data from another sheet
• Example: =Sheet2.A1

---

3️⃣1️⃣ Print Setup

• Page Orientation: Portrait / Landscape
• Margins, Header/Footer setup
• Print Preview before printing

---

3️⃣2️⃣ Document Protection

• Tools → Protect Sheet / Workbook
• Prevent unwanted edits

---

3️⃣3️⃣ Keyboard Shortcuts

• Ctrl+C → Copy
• Ctrl+V → Paste
• Ctrl+X → Cut
• Ctrl+S → Save
• Ctrl+Z → Undo
• Ctrl+Y → Redo
• Ctrl+PageUp / PageDown → Sheet navigation

---

3️⃣4️⃣ Sparklines

• Mini charts inside a cell to show trends
• Insert → Sparkline

---

3️⃣5️⃣ AutoText & Templates

• Frequently used text save करना
• Templates से standard spreadsheet बनाना

---

3️⃣6️⃣ Import / Export Data

• Import CSV, XLS, XLSX
• Export to PDF, CSV, HTML

---

3️⃣7️⃣ Sheet Views

• Normal, Page Layout, Page Break Preview

---

3️⃣8️⃣ Undo / Redo

• Ctrl+Z → Undo
• Ctrl+Y → Redo

---

3️⃣9️⃣ Future & Tips

• Use formulas, functions, conditional formatting for productivity
• Cloud Integration possible

---

4️⃣0️⃣ Diagram / Flowchart Ideas

• Flowchart for data processing: Input → Formula → Result → Chart
• Sheet & Cell relationship diagram

---