If 1 x 1 = 1 ; 2 x 2 = 4 ; 4 x 4 = 6 ; 5 x 5 = 5 ; 7 x 7 = 9 then 9 x 9 = ?

Question

If
5 + 4 => 9
3 + 5 => 9
9 + 1 => 9
1 + 6 => 8
4 + 2 => 8
1 + 7 => 7
5 + 6 => 6
3 + 7 => 3
7 + 0 => 0
Then
8 – 1 => ??

Answer 1

1(answer)
4*4=16(last digit 6)
5*5=25(last digit 5)
7*7=49(last digit 9)
9*9=81(last digit 1)

Answer 2

we take last digit of product
1 * 1= 1
2 * 2 =4
4 * 4 =6
5 * 5 =5
7 * 7=9
similarly

   9 * 9 =1

Answer 3

1 x 1 = 1 (1) 1
2 x 2 = 4 (4) 4
4 x 4 = 6 (16) 6
5 x 5 = 5 (25) 5
7 x 7 = 9 (49) 9
9 x 9 = 1 (81) 1

Answer 4

1x1=1 so 1
2x2=4 so 4
4x4=16 so 6
5x5=25 so 5
7x7=49 so 9
9x9=81 so 1

so the answer is 1