Numbers follow the characteristics of the main script. So, they should be sloped and based on an oval shape when written with Italics and round in shape and upright when written with Roman Capitals.
Numbers can be either ranged or non-ranged. Ranged numbers are typically used with Capital letters where there are no ascenders and descenders. Non-ranged numbers are used minuscule text where there are ascenders and descenders.
The method of construction is the same for ranged and non-ranged. We are showing you non-ranged numbers.
3, 4, 5, 7, 9
This group of letters all have descenders, meaning part of the number goes below the write-line.