Trouble using ISNUMBER and SEARCH within a range

I have cells (A1:A5) that have various number values in them. Some of these values may change to zero at a later date.

Question1: In A6, I would like to have a formula that searches A1:A5 to see if one of the values has changed to zero. If so, then I want A6 to show the value found in B1. If not, then A6 can be zero (or blank - it doesn't matter).

I tried this formula but it did not work:

=IF(ISNUMBER(SEARCH("0",A1:A5)),B1,0)


Question 2: In A7, I would like to have a formula that does the same thing as A6, but only if 2 or more of the cells in A1:A5 have been changed to zero.

Thanks in advance for your help.

1.
=if(countif(a1:a5,0)=1,b1,0)
2.
=if(countif(a1:a5,0)>1,b1,0)

Colin -

Thanks. That did work, except that I wasn't clear about one thing in my original question.

If there is only 1 zero, then the value in A6 should change. If there are 2 or more zeros, then the value in A7 should also change, but I need the new value in A6 (which changed when there was one zero) to remain there when A7 changes.

Any thoughts on this? Sorry for not making that clear originally.
When

Ok. I'm an idiot. I should have known that - I think I have been working in this stupid chart way too long today.

Thanks!