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.
Both those solutions work but format would hide the result if the sum of the cells is zero and I would guess you would want to show it the formula will show zero in the same circumstances.If the second didn't work then there is probably a number in the range, that's what count does, it counts numbers.oth those solutions work but format would hide the result if the sum of the cells is zero and I would guess you would want to show it the formula will show zero in the same circumstances.