1. Open spreadsheet software, such as Excel or Google Sheets.

2. Enter the name of each month in the first line, such as "1 month" and "February".

3. Enter the name of a day of the week in the second line, such as "Monday" and "Tuesday".

4. Select the cell in the first column, enter the date and fill in the date of the whole month. For a standard calendar, each month usually starts on Sunday in the first week and ends on Saturday in the last week.

5. Continue to fill in all months and dates according to the above steps.

6. Weekend dates can be marked in red or other colors, which is convenient to distinguish between working days and rest days.

7. If necessary, you can add text boxes or cells under certain dates to record special events or festivals.

8. Finally, beautify the form, use appropriate fonts, sizes and colors, and add border and background colors to make the calendar look more beautiful.

After making this form, you can print it out or save it as a PDF file, which is convenient for children to study and practice math at home.