Your first formula
Many people add up a purchase on their phone's calculator and then copy the finished number into a table. That's double the work, and it's easy to get a digit wrong while copying.
Excel will do the math itself if you type the calculation into a cell instead of the answer. This kind of entry is called a formula.
The equals sign comes first
A formula always starts with the = sign. That's how Excel knows the entry needs to be calculated. Without it, Excel stores the entry as plain text.
Select a cell, type =250*4 and press Enter. The cell shows the result, 1000. While the cell is selected, you can see the formula itself in the formula bar above the sheet.
The operation signs are almost the same as on a calculator:
- + addition;
- - subtraction;
- * multiplication (an asterisk);
- / division (a slash).
Decimals in a formula are written with a period: =1.5*2. To fix a formula, double-click the cell or click in the formula bar.
What Excel calculates first
Excel follows the order of operations you learned in school: multiplication and division first, then addition and subtraction. So two chairs at $250 and three desks at $890 take one formula with no parentheses: =2*250+3*890. Excel first works out the cost of the chairs and of the desks, then adds them up.
When you need a different order, use parentheses: Excel calculates whatever is inside them before anything else. Below, each chair comes with a discount. See how the parentheses change the total:
If a formula's answer doesn't match your rough estimate, check the order of operations first: often a pair of parentheses is missing.