Use the SUMIFS function to calculate the sum of all the values that meet a certain condition
The syntax is:
SUMIFS(column_to_add, column_to_search, condition)
= the values in this column will be added
= the value that will be searched
= the condition that will be applied on "column_to_search"
SUMIFS(T1!A, T1!B, ">10")
will return the sum of all the values in column A of table T1 for which the value in table T1 column B is greater than 10
so for the table:
SUMIFS(T1!A, T1!B, ">10") will return 50.
You can also have multiple conditions:
SUMIFS(T1!A, T1!B, ">10", T1!C, 3)
This will return sum of the values in column A for which the value in column B is greater than 10 and the value in column C is 3.
See the Tables page for more tips on how to work with tables.