If you have entered data in Sheet1 before grouping the worksheets, that data will be reflected in other sheets.
Answers
ENTERING DATA
Cells can contain two types of information: constant values and formulas. Constant values are numbers (including dates and times), logical values, error values, and text. Formulas are groups of constant values, cell references, names, functions, and operators that result in a new value when calculated or evaluated.
ENTERING CONSTANT VALUES
Numbers. Numeric entries can contain numeric characters (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, and 0) and the special characters (e.g., +, -, (, ), /, $, %, ., E, and e).
Negative numbers can be preceded by a minus sign or enclosed in parentheses.
Commas can be included in numeric entries as thousands separators.
Numeric entries containing leading dollar signs (or other currency signs, such as £ pounds) are formatted as currency.
Numeric entries containing trailing percent signs are formatted as percentages.
The worksheet numeric entries as fractions. If the fraction contains a leading integer (e.g., 1 1/3) it can be entered directly. If there is no leading integer, the fraction should be preceded by a zero (e.g., 0 2/3).
Numbers larger than the cell in which they are entered are converted to scientific notation unless a specific format is applied.
Use the Format_Column_Auto-Fit Width menu function to automatically set the column width to the correct size for all data in the column.
Dates and Times. Dates and times are automatically recognized by the worksheet. They are entered in the cell as values and automatically formatted. The following date and time formats are automatically recognized:
3/15/94 m/d/yy *
15-Mar-94 d-mmm-yy
15-Mar d-mmm
Mar-94 mmm-yy
9:55 PM h:mm AM/PM
9:55:33 PM h:mm:ss AM/PM
21:55 h:mm
21:55:33 h:mm:ss
3/15/94 21:55 m/d/yy h:mm *
* That these formats are locale-dependent. For example, in the United Kingdom, 15/3/94 would be recognized as the date format d/m/yy. Your locale is your country setting in the Windows control panel.