How use field from the last record to calculate interest

[stanleypatkan]

I'm trying to use a field from the last record displayed in a form to
calculate interest (Interest = NewBalance * 0.03 / 365 * 182). I've tried
Macros and build expression which didn't work. It will be placed in the last
record as a credit (Credit2203)

 

[Maarkr]

"last record displayed in a form "
Do you mean the last field on your form or a field value from the last
record in your table?
Maybe: Insert a text box on your form and in the Control Source Property
for that text box, put =[NewBalance] *.03/365*182 where NewBalance
is a field name on your form.