Sams younger sister also wanted to keep track of miles driven. However, She looked at the trip odometer reading on the dashboard rather than mile markers. Her mom had set it to zero when their car entered the highway

step-by-step explanation:

you can add the two numbers and divide the result by 2. or you can find the gap between the two numbers and add half of this to the smaller number.

i think asking google will you get the answer to that question