Question Discussion & Solution

All elements of a worksheet can be protected from accidental modification.
To protect a worksheet in Excel 2007 and higher versions, click the Review tab, click Protect Worksheet (or Protect Sheet), and click OK.
Excel 2003 and Earlier Versions click Tools > Protection, click Protect Sheet, and click OK.

Comments put in cells are called Cell Tip

Financial Functions are used to calculate depreciation, rates of return, future values and loan payment amounts.
A list of Excel Financial Functions in Excel are:
?Investment value functions including
1. FV
2. FVSCHEDULE
3. NPV
4. PV
5. RECEIVED
6. XNPV
?Internal rate of return functions including
1. IRR
2. MIRR
3. XIRR
?Asset depreciation functions including
1. AMORDEGRC
2. AMORLINC
3. DB
4. DDB
5. SLN
6. SYD
7. VDB
?Payment functions including
1. CUMIPMT
2. CUMPRINC
3. IPMT
4. ISPMT
5. PMT
6. PPMT
?Dollar conversion including
1. DOLLARDE
2. DOLLARFR
?Yield functions including
1. YIELD
2. YIELDDISC
3. YIELDMAT
4. ODDFYIELD
5. ODDLYIELD
6. TBILLEO
7. TBILLYIELD
?Price functions including
1. PRICE
2. PRICEDISC
3. PRICEMAT
4. ODDFPRICE
5. ODDLPRICE
6. TBILLPRICE

The Format Painter copies formatting from one place and applies it to another.
The Format Painter button on the standard toolbar in Excel 2003 and earlier version.
Home tab, in the Clipboard group, click Format Painter in 2007 and higher version.