Help calculating overall GPA (US transcript + Foreign Transcript)

I’m a transfer student applying to Cal State schools

I just wanted to clarify if my calculations are right.

Overall transferrable GPA = Grade Points attempted from all colleges / Units attempted from all colleges

note: Only taking into account transferrable grade points and units.

College 1
Units: 86
Grade Points: 341
GPA: 3.96

College 2 (foreign)
Units: 3.14
Grade Points: 94.2
GPA: 3.14

Overall transferrable GPA = (341 + 94.2 ) / (86+30) = 3.75

Surprisingly, when i use a different method, just add GPAs from both schools and divide by 2, i get a different result.

I’m not sure why this surprising; you can’t simply add and divide by 2 unless the units were the same for both College A and College B. I did not check the math, but the first method is how to calculate it.