Another option for entering numbers as text is to start each number with an apostrophe. This tells Excel explicitly to treat the number as text, and there is no need to switch to Text format. You can leave the cell format set to General.
When displaying numbers in Text format, note that Excel may let you use the cell values in simple formulas, but not in common functions like SUM.
The Excel SUM function returns the sum of values supplied. These values can be numbers, cell references, ranges, arrays, and constants, in any combination. SUM can handle up to 255 individual arguments.