Rights Issue Fraction to arrive to an average number of shares

Hello,

Can you please help me understand why, when there is a Rights Issue, we need to apply the bonus fraction being the Market Value of shares/TERP to a number of shares to arrive to an average number of shares? I mean, I understand that we need to adjust the number of shares retrospectively to make all periods comparable, but mathematically, I do not understand why we are multiplying number of shares by a $ shares fraction to arrive to an average number of shares. I am not good at maths but I would have thought that multiplying 5 shares x $5 gives me $10 and not 10 shares.

What am I missing?

Thanks in advance

Sara