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.
There is no largest number. One simple way to consider this is to  look at the function:    f(x) = x + 1    Pick any number, and plug it into that function. No â¦ matter what  number you plug in, the function will always give you a number that  is one larger than the previous one.