To enter a fraction in an Excel worksheet, first type 0
(zero), then the fraction: 0 1/20. (If you don’t put the zero in first, Excel
formats your entry as a date: 20-Jan).

To enter a mixed number, just type the whole number, then
the fraction, separating them with a space: 5 5/8.

Note that while Excel displays both fractions and whole
numbers on the worksheet, it actually stores them as decimals, as the Formula
Bar shows.