The American Optometric Association suggests that children should have their first regular eye exam at six months of age. Another vision exam should take place when a child is around two or three years of age when their vision undergoes its most rapid development and vision correction is most effective.
The ISNUMBER function is a quick, easy way to check if a cell contains a number. Our example used the IF function to illustrate how ISNUMBER can be used. If you haven't used IF in a formula before, you can read our lesson on the IF function here.
Display hidden cell values. Select the cell or range of cells that contains values that are hidden. How to select a cell or a range. To select. Do this. A single cell. Click the cell, or press the arrow keys to move to the cell.ide cell values. Select the cell or range of cells that contains values that you want to hide. How to select a cell or a range. To select. Do this.