Which NCTM math content standard—number and operations, algebra, geometry, measurement, or data analysis and probability—did you most enjoy learning

I think the numbers and operations is what I enjoyed learning most.

I makes sense to me to visually see a pie chart cut into sections.
knowing that 1/4 is the sames as 25% or .25.
The relations tied together makes sense if I can see the numbers and visualize the amounts in a form I understand.

Taking half of my apple away leaves me with half an apple. taking 1/4 away leaves me with 3/4.

Though learning it was challenging in some aspect, because using water or other parts like cutting an odd shape item can sometimes throw a child off. I know that it took a few methods for my Dad to show me in order for things to sink in.

Even now as an adult sometimes I forget the simplest aspects and get a little nervous when I use numbers and operations.