Vertical Spacing

Hello,

I'm new to graphic design. I'm trying to understand how best to vertically space my content. I have 4 numbers that are each 4" tall. How much space should i add between each number so that they look spaced properly. For instance, imagine I had:

1

2

3

4

How much space should be between the 1 and the 2? Or the 2 and the 3? Or the 3 and the 4?

Thank you so much for your help!