Brandon buys a radio for $46.15 in a state where the sales tax is 7%.

So then this is a simple multiplication problem. First, we need to make the percentage a decimal. To do that, we find out how many parts out of 100 it is. In this case it 7 parts, so we're making it the decimal .07. So the problem becomes 43.99x0.07. We multiply that, and come up with 3.0793. We'll round that to the hundredths place, and come up with 3.08. So on a radio that costs $43.99, you will pay $3.08 tax, bringing the total to $47.07.