But I Need To Multiply Them!

Logic Level 1

$\begin{array}{ccccc} & & & 1 & 2&3\\ \times & & & & 4 &5\\ \hline & & \bigstar & \bigstar & 3&5\\ \hline \end{array}$

Find the value that represents the symbol $\bigstar$ .

Can you do it without multiplying the expression?