suggestion : just use your own calculations. If ever audited by the IRS, you have documentatin on how you did it. You are not beholden to TT's method.
it is rather easy: the aquisition interest is the interest rate times the $150,000; since it is not amortizing, it is that simple. Whatever was reported by the bank less the aquisiiton interest is the non-aquisition interest.
TT's calculation should be close to what I stated above but I agree it could have been simpler.
