if jack has three children and theirs ages product is 455, how old are the children, and how do you make that calculation

Look for the factors of 455

$${factorize}{\left({\mathtt{455}}\right)} \Rightarrow \left\{ \begin{array}{l}{\mathtt{5}}\\ {\mathtt{7}}\\ {\mathtt{13}}\\ \end{array} \right\}$$

5*7*13 = 455

So it looks like their ages are 5, 7 and 13.