Whenever you do a series of calculations, you are using a formula, whether or not you ever write it down. To write a formula for Excel to use, you must know two things: where to find the numbers to use (by cell reference or cell name) and what to do with them (which operations to use).

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Operations

The basic operations and their symbols are:

power ^    add +    subtract -    multiply *    divide /

Raising a number to a power is just multiplying the number by itself. So if the value in cell G4 is 8, then G4^4 means 8*8*8*8 = 4096, that is, 8 times itself 4 times.

While technically not operations, you will also need to understand negation - (the negative of a number) and percentage % (the form of the number as a percent). If cell D10 contains the number 23, then in a formula -D10 is the number -23. If cell D10 contains the number -15, then -D10 means -(-15) which is the same as 15. The percentage form of a number moves the decimal place in the number. So 125% is the same as the number 1.25 and 50% is the same as 0.5 and 0.50 and 0.50000.

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Order of operations

When there are several operations involved, you have to know what order to do them in.

	Order of operations:
1	Any calculations inside parentheses ( )
2	Negation -
3	Percentage %
4	Powers ^
5	Multiply and divide * /
6	Add and subtract. + -

When a formula uses more than one operation, the operations must be done in the right order. For example, in 3 + 5 / 8 you must divide first and then add 3, which results in an answer of 3.625. This is not the same as (3 + 5)/8 for which you add first (because of the parentheses) and then divide, resulting in an answer of 1.

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Formula Examples

Here are some sample Excel formulas and what they mean. The equals sign is required. Parentheses are required around arguments for a function, like the range of cells in the AVERAGE function. If you have named cells or ranges, then you can use those names in a formula. If the cells are in a table, you can use column and row labels in a formula.

Formula	Means:
= B3*C14	Multiply the value in cell B3 by the value in C14
=Quantity*Cost each	Multiply the value in this table row of the column labeled "Quantity" by the value in this table row of the column labeled "Cost each".
= D12-B3	Subtract the value in cell B3 from the value in D12
= B3^3	Raise the value in B3 to the power 3. This is the same as B3*B3*B3
=(A10 +B5)/C4	Add the values in cells A10 and B5 and then divide by the value in C4.
=SUM(B3:C14)	Add together the values in the range
=AVERAGE(D4:G45)	Add up the values in range D4:G45 and divide by the number of values there were.
=MAX(J300:M350)	Find the largest value in the range J300:M350
=MIN(F12:F20)	Find the smallest value in the range F12:F20
=COUNT(K20:L50)	Count the number of cells that contain a value in the range K20:L50. (This will skip any blank cells or cells with text, but will count cells containing a zero.)