Numeric fields have multiple options for controlling data entry, specifically the following ones:
Default value
Format (integer vs. decimal)
Minimum / maximum (the minimum or maximum value that will be accepted)
Default Value
This allows you to set a value so that every time a new record is created, this particular field will be pre-populated with the value added here. It helps save time when creating records that will share the same information. However, if you want to add a different value, it is possible.
Format
This is used to format the numeric field to accept integer or decimal values. This means that if you require that the field allows you to save a value such as 125.45, you need to make sure that your format setting is set to decimal. If you don't want to accept decimal values then, set it to integer.
Minimum/Maximum Values
This is a validation that allows you to set a range of valid numeric values for a given numeric field. For example, let's say that you have a field to capture the diameter of a pipe used in a given space on a construction site. Because you have the blueprints you know that the smallest one is 3 inches while the biggest in diameter is 8 inches. You can set these values as minimum and maximum to prevent the data collectors or users from entering a value that is outside this range.
Notes
Numeric fields can only accept mathematical numbers, it can not be used for capturing values like formatted phone numbers. It will be better to use a text field type.
Numeric fields do not support leading zeros or trailing zeros (degrees of precision). For this, a text field type would be better.