How do you do these problems by hand?

So I'm supposed to do these by hand and only print the answer on Matlab. This is a homework we were assigned a long time ago but I never did it nor has the solution been posted for it. I have a test tomorrow and I really would like to know how to do them by hand.

1)

x = 10; 
if round(x/5) == x/5 x = 2 * x + 4; 
elseif x == 10 x = 4 * x; 
else x = 0;
 end

---------------------

2)

x = 10;
 if round(x/3) == x/3 x = 2 * x + 4; 
elseif x == 10 x = 4 * x; 
else x = 0; 
end

-------------------------

3)

x = 9;
 if round(x/4) == x/4 x = 2 * x + 4;
 elseif x == 4 x = 4 * x;
 else x = 0; 
end 

[Walter Roberson]

You use your knowledge of MATLAB operations.

What does / do? What does round() do? What does == do?

In the circumstance that you have a chain

if condition1; result1;
elseif condition2; result2;
else result3;
end

then if condition1 and condition2 and "else" are all true, then what would the outcome be?