Add a leading quote before cell formula, numeric value, and TRUE/FALSE to prevent formula evaluation or number formatting.

For example,

Type '=A1 in a cell then it will show as “=A1” instead of formula result of A1.
Type 'True or 'False will show as “True”/“False” instead of TRUE/FALSE binary value.
Type '100000000 will show as “100000000” instead of “1E8”.