running into issues with excel and calculating for formula and i cant get it to work no matter what i do

Use these checks and fixes in order:

1. Make sure the formula is written correctly in B43, for example:

      =SUM(C39:K49) + K41
   

   The equal sign at the start is required; without it Excel will just show text instead of calculating.
2. Check that B43 (and the cells in the range) are not formatted as Text:
   1. Select B43.
   2. On the Home tab, open Number Format and choose General.
   3. Press F2 in B43, then Enter to re‑enter the formula. Do the same for any cells in C39:K49 or K41 that should be numeric but might be Text.
3. Confirm that workbook calculation is set to Automatic:
   1. Select File > Options > Formulas.
   2. In Calculation options, under Workbook Calculation, select Automatic.
   3. Click OK, then press F9 to recalculate.
4. If an error indicator appears in B43, hover over it or use the formula bar check button to see the error description and correct any highlighted part of the formula (for example, missing parenthesis or wrong operator).

After these steps, B43 should calculate the sum of C39:K49 plus K41.

References:

• How to avoid broken formulas in Excel
• Detect formula errors in Excel
• Enter a formula