When working with fractions in Excel, you have a few different options for how to format your cells. You can use the regular number format with a slash (/) between the numerator and denominator, or you can use one of Excel's fractional number formats. To format a cell as a fraction, select the cell(s) you want to format and then click the "Format" button on the Home tab of the ribbon. In the Format Cells dialog box, select "Number" from the Category list and then choose one of the fractional number formats from the Type list.
The first thing to understand about working with fractions in Excel is that, internally, all fractions are stored as decimal values. For example, the fraction 1/4 is stored as the decimal value 0.25. When you format a cell as a fraction, what you're really doing is telling Excel how many decimal places to display. For example, if you format a cell as the fraction 1/4, Excel will display 0.25 in that cell. But if you format the same cell as 1/8, Excel will display 0.125 instead.
One advantage of using one of Excel's fractional number formats is that it's easy to change the level of precision without having to re-enter your data. For example, if you have a column of cells formatted as 1/4 and you want to change them all to 1/8, just select the cells and then choose 1/8 from the Type list in the Format Cells dialog box. All of the cells will update instantly.
Another advantage is that when you use a fractional number format, Excel will automatically reduce fractions to their lowest terms. So, if you enter the data 1/4 into a cell formatted as 1/8, Excel will automatically change it to 0.125 (1/8).
If you want more control over how your fractions are displayed, or if you need to work with mixed numbers (numbers with whole number and fractional parts), you can use the custom number format feature in Excel. To learn more about using custom number formats in Excel, see our article here.