Jason's insurance pays 80% of the cost after he pays a $200 deductible. The deductible is Jason's responsibility. The insurance does not pay this and calculates the 80% AFTER it is subtracted from the total cost.
That's 1200 - 200 = 1000.
The insurance pays 80% of 1000. Percent means "out of 100" (per means "for every" and "cent" means 100 --> think CENTury...100 years). So 80% means 80 out of 100. That is,
. To find 80% of 1000 we multiply: 
If decimals are more your thing then represent 80% as .80 and multiply (1000)(.80) = 800.
Now, that's what the insurance pays. So out of that $1,000 the insurance pays $800 leaving Jason with a bill of $200 plus the deductible (another $200). That means Jason pays $400.
That's 1200 - 200 = 1000.
The insurance pays 80% of 1000. Percent means "out of 100" (per means "for every" and "cent" means 100 --> think CENTury...100 years). So 80% means 80 out of 100. That is,
If decimals are more your thing then represent 80% as .80 and multiply (1000)(.80) = 800.
Now, that's what the insurance pays. So out of that $1,000 the insurance pays $800 leaving Jason with a bill of $200 plus the deductible (another $200). That means Jason pays $400.