SUMIF(range, criteria, [sum_range])
Argument Descriptions:
=SUMIF(B1:B6,">900")
This figure shows a list of items and their prices. We only want to sum those items whose price is exactly 99 cents. The formula entered into cell B10 is =SUMIF(B2:B8,0.99) . Since we are only summing those values which are exactly .99 there is
no need for any additional logical symbols because the equal sign is optional. Because the criterion is only a number it does
not need to be placed within double quotes.

When using the optional Sum_Range argument you base your criteria on a different range of cells than those that you are summing.
We want to find the total number of males and females in a high school. The figure below shows the worksheet for this. The worksheet uses separate formulas for determining the number of males and females. The arguments used in the formula for determining the number of males are:
=SUMIF(B2:B9,"M",C2:C9)
The only difference in the formula for computing females is the criteria which is “F”. The formula entered in cell C12 is =SUMIF(B2:B9,"F",C2:C9)
The arguments used in the formula for determining the number of Freshman and Junior class members are:
SUMIFS(sum_range, criteria_range1, criteria1, [criteria_range2, Criteria2]…)
=SUMIFS(B2:B11,A2:A11,"<>Hobart",B2:B11,">=20000",C2:C11,">=03/01/2010")
The rows that meet all the criteria are highlighted in the worksheet below. They are the only deposits that meet all three criteria of (1) Not being a Hobart branch, (2) Having a deposit greater than or equal to 20000 and (3) deposited on or after 3/12/2010. The result of adding the deposit for these three rows is 83562.79