Can't it simply be written like this?

    mid = low/2 + high/2

Division is not associative:

https://www.khanacademy.org/math/arithmetic-home/multiply-di...

While that is true it is not relevant here, since this example does not involve associativity.

What is relevent here is that integer division is not distributive over addition.

Nope, try low = 1, high = 1 and you get mid = 0.

i think you can fix it with: (low >> 1) + (high >> 1) + (low & 1 & high)

for unsigned numbers. not sure if it works for signed numbers.

For low=3, high=5 case, this gives mid=3.

You are not alone. See my comment.

Having dual monitor setup isn't the real issue. Also, turning your head occasionally can be a relaxing experience. The real problem is having a dual monitor setup and still using just one of them, which makes you keep your neck turned for a long time (assuming your monitors are positioned in an inverted V shape). If you have a dual monitor setup, keep the primary one straight in front of you, and place the secondary one away, dedicated for things that require less attention.

I have always seen the second monitor as “extra” space and not to be used equally. I previously used two 34” ultra wide (21:9) monitors with one centered and one off to the right. The left half of the extra monitor was basically reserved for slack and dashboards and the right half of the extra monitor was seldom ever used.

I still use that setup for gaming, but I use a single Pro Display XDR for work now and I think the only time I might miss the extra screen space is probably Zoom