Use mental math to guess the starting value for the table.
-1
Practice makes perfect
We want to use a table to solve the given equation.
0=10+10y
In order to choose a good starting point for our table, let's pretend that the equation is 0=10y. What multiplied by 10 would get us close to 0? 0 is a good guess, so let's try it in our table. We should also try one digit less and one digit greater, just to be on the safe side.
y
10+10y
=
1
10+10 (1)
20
0
10+10 (0)
10
-1
10+10 (-1)
0
We can see that y=-1 is the solution to our equation.