How to make a number out of other numbers in mathematica? I’m not entirely sure if this is possible, but I would like to make numbers composed of other numbers. For example, given $a$, $b$, and $c$, I’d like to make a number such that the digits are $a.bc$. 
So, if $a = 1$, $b = 2$, and $c = 3$, we would have the number $1.23$. Is this possible? 
Thanks!

Yes, as long as you know what you want to do and you do the mathematics correctly, go ahead and create new numbers out of the old ones.
That is a good way to understand numbers better. 
They have created the set of positive integers starting at 1 and adding one each time.
$$1, 1+1=2, 2+1=3,....$$  
