Mark's approach is generally the approach I take when data doesn't calculate. Usually, I have a personal list of items to follow to troubleshoot:
1. Check that I have Formula Type turned on and not using (Not Used)
2. Is my Formula Pass in Formula Type correct? If I'm troubleshooting, I will move to Formula Pass 16 to make sure that all other dependent calculations are executed before running this calculation.
3. Then, I will run through the process that Mark has provided. Start with making sure that each data buffer in the mathematic operation executes by itself. Then put the data buffers back together in the subtraction mathematic operation.
On a side note, you are missing the UD1 dimension in this data buffer A#Total_Assets:F#EndBalLoad:I#Top. UD1#Calculation is defined in 1 source data buffer. UD1#Manual_Input is defined in the destination data buffer.