How to Add up Multiplications in Excel

1. Launch Excel 2010 and open the spreadsheet that contains the products that you want to add together.
2. Click once in the cell where you want the sum of the products to appear. Click the 'Insert Function' button on the Formula bar, which opens a list of available functions. Click the 'SUMPRODUCT' option, which opens a separate window.
3. Click the 'Array1' field in the Function Arguments box. Select the range of numbers for which you want to find the sum of the products, for example 'A1:B4.' Repeat this step for each range of numbers, using a different Array field for each group. For example, select 'C1:D4' for the Array2 field. Click the 'OK' button to accept the formula.