Use `SUMIF` to add values that meet one condition
Syntax: `=SUMIF(range, criteria, [sum_range])`
`range` is the cells to check against the condition
`criteria` is the condition to match
`sum_range` is the cells to add if the condition is met
Example: `=SUMIF(A:A, “Apples”, B:B)`
This adds values in column B where column A equals “Apples”
Use comparison operators in criteria, such as `”>10″` or `”<5"`
Use cell references in criteria, such as `”>”&D1`
Use wildcards like `*` and `?` for text matching
Leave `sum_range` out if you want to sum the same cells being checked
Use `SUMIF` for one condition only
Use `SUMIFS` when you need multiple conditions