 Math doesn’t have to be difficult if you use Excel.
 Excel Formula Syntax
 Using cell references next to formulas
 Enter cell references with a period and click
 Use the addition formula in Excel
 change formula
 Create more complex formulas
 Create Fibonacci Sequence
Math doesn’t have to be difficult if you use Excel.
As with all basic math operations in Excel, if you want to add two or more numbers, you create a formula. Formulas quickly find the sum of several digits.
The instructions in this article apply to Excel 2019, 2016, 2013, 2010, 2007; Excel for Office 365 and Excel for Mac.
Excel Formula Syntax
Here are some important points to remember about Excel formulas:

Formulas in Excel start with an equal sign ( † †

An equal sign is entered in the cell where the answer will appear.

The add sign in Excel is the plus sign ( † †

Formulas are completed by pressing the Enter key.
Using cell references next to formulas
In the sample data below, rows 24 use the formula in column C to add data to columns A and B. In row 2, the result is calculated using the addition formula = 5 + 5.
Lines 3 and 4 show how to enter data into table cells first and then use the addresses or references of those cells in the formula. For example = A3 + B3.
An advantage of using cell references instead of the actual data in a formula is that if you want to change the data, you replace the data in the cell instead of rewriting the entire formula. Formula results are automatically updated when the data changes.
To add multiple numbers arranged in the same column or row on a worksheet, use the SUM function, which provides a shortcut for creating a long addition formula.
Enter cell references with a period and click
Although you can enter the above formula in cell C3 and display the correct answer, it is easier to use a period and click to add cell references to formulas. This reduces the chance of errors caused by an incorrect cell reference.
Point and click to select a cell that contains data so you can add the cell reference to the formula instead of manually typing it into the cell.
Use the addition formula in Excel
Creating the example below in cell C3 is very easy if you use a formula to sum the values of cells A3 and B3.
To create an addition formula:

Select cell C3 and enter an equal sign ( † ) to start the formula.

Select cell A3 to add a reference to that cell in the formula after the equals sign.

Enter character plus ( † ) in the formula after A3 †

Select cell B3 to add a reference to that cell in the formula after the add character.

Click Enter to complete the formula.

The answer 20 appears in cell C3.
Select a cell to display the formula in the formula bar above the worksheet.
change formula
If you want to change or correct the formula, you have two options:

Doubleclick a formula in a worksheet to put Excel into edit mode and then make changes to the formula.

Select the cell containing the formula and recreate the whole formula.
Create more complex formulas
To write more complex formulas that contain other math operators, use the steps above to get started and then proceed to add the appropriate math operators, followed by cell references that contain new data.
Before combining several math operations in a formula, make sure you understand the sequence of operations that Excel follows when evaluating a formula.
Create Fibonacci Sequence
The Fibonacci sequence, created by the 12thcentury Italian mathematician Leonardo Pisano, forms a continuous series of increasing numbers. These series are used to mathematically explain various patterns in nature, such as:

Spiral shape of sea shells.

Arrangement of leaves on a tree branch.

Photo of breeding bees.
After the first two numbers, each additional number in the sequence is the sum of the previous two numbers. The simplest Fibonacci sequence, shown in the image above, starts with the numbers zero and one.
Since the Fibonacci sequence involves addition, it can be created using the addition formula in Excel, as shown in the image above.
The following steps describe how to create a simple Fibonacci sequence using a formula. The steps include creating the first formula in cell A3 and then copying that formula to the remaining cells using the fill handle. Each iteration or copy of the formula adds the previous two numbers in the sequence.
To create the Fibonacci sequence shown in the example:

In cell A1, enter zero ( 0 ) and press Enter †

Type in cell A2 a and press Enter †

In cell A3, enter the formula = A1 + A2 and press Enter †

Select cell A3 to make it active.

Hover your mouse over the fill handle (it’s the dot in the lower right corner of cell A3). The pointer changes to a black plus sign (+) when it’s over the fill handle.

Drag the fill handle to cell A19.

Cell A19 contains the number 2584.