Hi , I just need help figuring this out because I'm not mathematical but I need to so I can cast on the right number of stitches

The first step is to measure your shoulder-span. Mine is about 17 inches. Then you add 4 inches for each sleeve (8 inches) and add that to your shoulder measurement. I got 25 inches from that, so 25 inches will be the width of my bolero. My ribbing gauge is 4 stitches per inch, so I multiply 25 by 4 to get 100. I take that number, 100, and round it down to the next number that is a multiple of 4 +2. The next number down is 98, and that will be my cast-on number.

Those are the instruction- my measurements are 22 so+ sleeves would be 30 (30x4=120) multiple of 4 +2 is where I get confused how many should I cast on?