Excel: apply result of IF statement on multiple cells

I want to apply the result of an IF statement on multiple cells, so for example A2, A2 and A3 are equal to 1, 2 or 3.

When A2 is equal to 1 I want to get B2,B3,B4 = 1,0,0

When A3 is equal to 2 to get B5,B6,B7 = 0,1,0

And when A4 is equal to 3 to get B8,B9,B10 = 0,0,1

Is this possible? I am kinda new to excel