Aperture

I am playing with aperture for AYWMC class (see my profile if you want to know what that is). This would have been easier outside with more light, but I it is relatively cold today and I am not feeling adventurous. A bit of a headache started. Hmm, maybe fresh air would be helpful.
My extra photo is a more aperture practice.

Being a math teacher, I have a good understanding of the concept and calculation, but it never hurts to purposely practice.