Answer:
We calculate the slop of a line.
How to find the slope:
Pick any two points on a graph
The formula of slope is 
For example we have two points that contains the coordinates (5,2) (7,4)
Inserting them to the formula would result in:

=
Our rate of change is rise 2, run 2.
Well 1A is wrong as 13+4=17 and 11+7=18 and 2B is also wrong as 6 squared is 36 and 4 squared is 16,36+16=52 6+4=10 10 squared is 100 on (6+4) squared you would do the addition as there is BIDMAS brackets indices division multiplication addition and subtraction
Tracking a change over time.
2.57*10^4 is 1,000,000 times more than 2.57*10^-1
Why?
4-(-1)=5 2
2.57*10^4=25700
2.57*10^-1=0.0257
and
25700
÷ 0.0257
=1000000
and 1000000=10^6