Adjusted net income book error?

I am using Osborne book atm. In relation to higher tax payers’s personal allowance, I know we must work out adjusted net income first. According to the text book, it should be total net income - grossed up ppp - grossed up gift aid - personal saving allowance - dividend allowance on page 5.8. However in the workbook question 5.5. It appears that only need to - grossed up ppp - grossed up gift aid. I’m so confused, ther must be an error somewhere, but I don’t know which vision is incorrect. Because I’m completely self studying, I have no way to find out the correct answer except coming here. Can anyone help please? Exam booked for next Friday.