It wasn't meant as literal 20 doors exactly, but more an expression of wanting to multiply what I started with.But I get where you're coming from in that last paragraph.

The amount of work and stress will multiply so I would just be cautious about that

You can use monthly periods and the resulting IRR equation will deliver a monthly IRR which you can simply multiply by 12 to find the annual IRR.  

For MTR - look up the same property for LTR rates and  multiply it by 30%.

So you'd be multiplying $20, 000 by 20% to get $4,000.

The managing member needs to be able to understand the depreciation + rental income for the year and multiply by the partner percentage of profit/loss. 

When you enter the address of a property, the site estimates the rent by multiplying the average area $/SF by the subject property's square footage.

hard money usually doesn't lend on more then 12 months they are short term loans, borrowed multiplied by determined interest rate, the final number is your total interest paid over 12 months, divide it by 12 and voila you have your monthly payment

Then he multiplied by the calender days until sale, let's say 300 days. $10 x 300 = $3,000.I think the math makes sense.

Your millage rate is a multiplier to your “just value”.