How to Complete Form I-864A

I sponsor to my Mom and Dad. As a co sponsor my husband is filling I-864A. On page 3 part 5 question 1) who's name is comes as a sponsor? 2) very next is for indicate Number means what? We are 4 of us in our family. Me my spouse and our two minor daughters. I am sponsering my parents. So I have to write down for how many? They ask for intending immigrants number ? Means my parents right? Part 5 question 1a) intending immigrant number 1? How come they have a number or u.s. Social number or uscis Eli's number?
On page 4)
Part 5 they ask for sponsors promise, statement, contact information , means who's? My or my husband who is co sponsor?
Part 6)
Household member means who?

Here are the instructions for the form. Read them and follow them. If you find the form to be too complex despite those very clear instructions, you should retain a professional to help you complete the form.

Thanks for the quick reply, I appreciate. I have that instruction with me. Still I confused. Don't know how to fill it. I already fill everything just this question is left and I need your help please.