Depth of Field

We had some sun and blue skies today but I got engrossed in some experiments indoors with regard to various lenses I own and depth of field. Today's photos were shot with the 90mm macro lens. On the left, with the lens open to its maximum aperture f2.8. On the right with the lens closed down to its minimum aperture f32. Below is midway between the two - f16. These are the images I expected to result but for me it was valuable to actually see the difference aperture size makes. In all these photos, the number "9" was nearest to the lens and the number "3" was most distant.