How Do You Calculate Loan Paydown?

[Brad Waterstraat]

I saw an Instagram post by Craig Curelop showing the numbers on a client purchase (see below).

I am confused on loan paydown. How exactly is that 8k calculated?

Purchase Price: $430,000

Down Paymet: $11,000

Rehab: $9,000

All In: $20,000

After Repair Value: $475,000

Rent + Rent Savings: $3,600

PITI: $2,300

Reserves: $500

Cash Flow: $800

Annual Net Worth ROI:

Cash Flow: $9,600

Loan Paydown: $8,000

Appreciation: $45,000

Initial Payment: $20,000

NWROI: 313%