Calculate rules let you automatically populate a numeric field by calculating
its value based on other fields. Calculations are limited to numeric fields.

To follow the example below:

Create 5 Numeric fields called Animal Weight 1 (US lb.), Animal Weight 2
(US lb.), etc.

Create a Numeric field called Total Food Required (US lb.).

The calculation is defined using the embedded calculator. Use a mix of numeric
field values, mathematical operators, and constants to define calculation
rules.