calculations within the formula bar

not fully understanding what you want to do
But the formula bar, just shows the calculation in a cell

2321 + 1073 / 2 = 1697

You need to put the 2321 + 1073 in brackets

Excel will do the * or / first then the + or -
so you need to add brackets so excel knows to do that

2321 + 1073 /2

will do 1073/2 first = 536.5
and then subtract from 2321
= 2857.5

to get the answer you need
2321 + 1073 / 2 = 1697
then
= (2321 + 1073 ) / 2 = 1697

forcing excel to do the () first

the 74% is correct if the cell is formatted to show %

The order in which excel executes math functions is

Parentheses
Exponents
Multiplication and division
Addition and subtraction

2321 2073
% difference or change would be

(2321 - 2073 ) / 2073

12%

2073 has increased by 12% to get to 2321
OR
2321 has decreased by 11% (10.6) to get to 2073

OR

the difference in % from what
where does 1073 come from ?

I think candybg has nailed it , as thats what your formula examples appear to do
Which i did not follow

thanks for the rep

your welcome