Question

what fraction will you add to 1 / 7 to get 1 whole

Answer 1

Let the fraction be x

so by the condition given in your question we get equation

1/7 + x = 1

x = 1 - 1/7

x = 6/7

so your required answer is 6/7

Answer 2

Hey !!!

This is Your answer.

We have a find a number which make 1/7 whole when added to it.

Let the number be x.
So, 
1/7 + x = 1
x = 1 - 1/7
x = 7/7 - 1/7
x  = 6/7.

Hope It Helps