How do you change all cells to absolute reference?

To change all cells to absolute reference in a spreadsheet program like Microsoft Excel or Google Sheets, you can use a combination of the "$" symbol and cell references. For example, if you have a formula in cell B2 that references cell A1, you can make the reference absolute by adding "$" before the column letter and row number like this: $A$1. By doing so, when you copy or drag the formula to other cells, the reference to cell A1 will remain fixed. This ensures that the formula always refers to the same cell regardless of its position. To change all cell references within a formula to absolute references, you can use the find and replace function, replacing the cell references without "$" with the corresponding absolute references containing "$".