3,256,423,865 rounded to the nearest million is 3,256,000,000. How I know is that the 4 in the hundred thousands place is lower than 5. So the 6 would of stayed the same and the rest of the number behind 4 would of been 0, including the 4.

Here, in the given figure. Angle y° forms vertical opposite angle pair with Angle 163°, therefore they have equal values.
that means ~

Negative numbers. Remember that whole numbers are 0 and positive numbers.