Jumbled DOL and DFL formulas? presented, remember, comment, change, income

MonkeyBusiness

DOL =  Percentage change in operating income / Percentage change in units sold
        =  Q(P-V) / Q(P-V)-F
Aren’t the numerator and denominator jumbled and don’t agree with corresponding text description?      
DFL  = Percentage change in net income / Percentage change in operating income
        = Q(P-V)-F / Q(P-V)-F-C
Same comment here. Isn’t Q(P-V)-F the operating income and Q(P-V)-F-C the net income?
If I remember correctly, this is also the way they are presented in the CFAI readings. If this is the case, should we follow the formula over the text description?

Zestt

Okay, I trust you Sir. There’s no time to think it through now.
Thanks Hei so. Wish i had stumbled upon this forum a long time ago. Would have saved much time.

John10

I asked this a while ago. I still don’t really get it. I’m just going to memorize the formula and be done with it. It’s not just net income, it’s the change in net income

cjs238

Thanks for your explanation. But if I may, I’d like to ask further to clear out something that’s bugging me or maybe I’m just missing out on something. Isn’t it that if we deduct the C (fixed financial cost) from OI, we will get the NI? If that’s the case, then why is the numerator without minus C described as the %change in NI and the denominator with minus C, described as the % change in OI.